Advanced Energy Harvesting Technology

Topic Information

Dear Colleagues,

Energy harvesting has been a promising technique for next-generation wireless and wearable electronic devices since it can deliver sustainable energy to power low-power electronic devices by capturing ambient forms of energy that would otherwise be lost, such as light, heat, sound, vibration, etc. Energy harvesting is a multi-disciplinary technology that combines a wide range of research fields, e.g., the development of advanced energy materials, smart structures, and circuits for power management to achieve sufficient harvesting efficiency and innovations in applications to broaden the potential of the energy harvesting technology. Here, we are pleased to invite the research community to submit a review or original research article on, but not limited to, the following relevant topics related to Advanced Energy Harvesting Technology:

• Advanced materials for energy harvesting
• Kinetic, thermal energy harvesting, etc.
• Power management for energy harvesting systems
• Self-powered sensors
• Applications of energy harvesting

Dr. Mengying Xie
Prof. Dr. Kean C. Aw
Prof. Dr. Junlei Wang
Prof. Dr. Hailing Fu
Dr. Wee Chee Gan
Topic Editors

Keywords

Participating Journals

Journal Name	Impact Factor	CiteScore	Launched Year	First Decision (median)	APC
Applied Sciences applsci	2.5	5.3	2011	18.4 Days	CHF 2400
Energies energies	3.0	6.2	2008	16.8 Days	CHF 2600
Materials materials	3.1	5.8	2008	13.9 Days	CHF 2600
Micromachines micromachines	3.0	5.2	2010	16.2 Days	CHF 2100
Sensors sensors	3.4	7.3	2001	18.6 Days	CHF 2600

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Supplementary material:
Supplementary File 1 (ZIP, 164589 KiB)

18 pages, 6300 KiB  

Open AccessArticle

Shell-Optimized Hybrid Generator for Ocean Wave Energy Harvesting

by Heng Liu, Dongxin Guo, Hengda Zhu, Honggui Wen, Jiawei Li and Lingyu Wan

Energies 2025, 18(6), 1502; https://doi.org/10.3390/en18061502 - 18 Mar 2025

Viewed by 202

Abstract

With the increasing global emphasis on sustainable energy, wave energy has gained recognition as a significant renewable marine resource, drawing substantial research attention. However, the efficient conversion of low-frequency, random, and low-energy wave motion into electrical power remains a considerable challenge. In this [...] Read more.

With the increasing global emphasis on sustainable energy, wave energy has gained recognition as a significant renewable marine resource, drawing substantial research attention. However, the efficient conversion of low-frequency, random, and low-energy wave motion into electrical power remains a considerable challenge. In this study, an advanced hybrid generator design is introduced which enhances wave energy harvesting by optimizing wave–body coupling characteristics and incorporating both a triboelectric nanogenerator (TENG) and an electromagnetic generator (EMG) within the shell. The optimized asymmetric trapezoidal shell (ATS) improves output frequency and energy harvesting efficiency in marine environments. Experimental findings under simulated water wave excitation indicate that the accelerations in the x, y, and z directions for the ATS are 1.9 m·s⁻², 0.5 m·s⁻², and 1.4 m·s⁻², respectively, representing 1.2, 5.5, and 2.3 times those observed in the cubic shell. Under real ocean conditions, a single TENG unit embedded in the ATS achieves a maximum transferred charge of 1.54 μC, a short-circuit current of 103 μA, and an open-circuit voltage of 363 V, surpassing the cubic shell by factors of 1.21, 1.24, and 2.13, respectively. These performance metrics closely align with those obtained under six-degree-of-freedom platform oscillation (0.4 Hz, swing angle range of ±6°), exceeding the results observed in laboratory-simulated waves. Notably, the most probable output frequency of the ATS along the x-axis reaches 0.94 Hz in ocean trials, which is 1.94 times the significant wave frequency of ambient sea waves. The integrated hybrid generator efficiently captures low-quality wave energy to power water quality sensors in marine environments. This study highlights the potential of combining synergistic geometric shell design and generator integration to achieve high-performance wave energy harvesting through improved wave–body coupling. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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18 pages, 7566 KiB  

Open AccessArticle

Effects of Aerodynamic Parameters on Performance of Galloping Piezoelectric Energy Harvester Based on Cross-Sectional Shape Evolutionary Approach

by Xiaokang Yang, Bingke Xu, Zhendong Shang, Junying Tian, Haichao Cai and Xiangyi Hu

Micromachines 2025, 16(3), 254; https://doi.org/10.3390/mi16030254 - 24 Feb 2025

Cited by 1 | Viewed by 383

Abstract

This study explores the potential effects of the aerodynamic parameters on the performance of the galloping piezoelectric energy harvester. By considering the geometric configurations, a bluff body cross-sectional shape evolution approach is proposed using Boolean operations on the polygons and forty-eight different cross-sectional [...] Read more.

This study explores the potential effects of the aerodynamic parameters on the performance of the galloping piezoelectric energy harvester. By considering the geometric configurations, a bluff body cross-sectional shape evolution approach is proposed using Boolean operations on the polygons and forty-eight different cross-sectional shapes with the protruding and depressed features are considered. Computational fluid dynamics is employed to perform a time-varying simulation of the aerodynamic characteristics. The effects of the aerodynamic parameters on performance are investigated computationally using a distributed parameter electromechanical coupling model. The critical wind speed, maximum output power, and the slope of the power versus wind speed curve are introduced as the performance evaluation parameters. The results show that the rear-side protruding feature and the top-side and bottom-side depressed feature have significant potential to enhance the performance. Furthermore, a symmetrical structure of the cross-sectional shape in the downstream direction should be prioritized over asymmetric designs. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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27 pages, 617 KiB  

Open AccessArticle

A Joint Approach for Energy Replenishment and Data Collection with Two Distinct Types of Mobile Chargers in WRSN

by Yuxiang Li, Tianyi Shao, Weixin Gao and Feng Lin

Sensors 2025, 25(3), 956; https://doi.org/10.3390/s25030956 - 5 Feb 2025

Viewed by 525

Abstract

Wireless rechargeable sensor networks (WRSNs) address the energy scarcity problem in wireless sensor networks by introducing mobile chargers (MCs) to recharge energy-hungry sensor nodes. Scheduling MCs to charge the recharge nodes is the primary focus of the energy replenishment scheme in WRSNs. The [...] Read more.

Wireless rechargeable sensor networks (WRSNs) address the energy scarcity problem in wireless sensor networks by introducing mobile chargers (MCs) to recharge energy-hungry sensor nodes. Scheduling MCs to charge the recharge nodes is the primary focus of the energy replenishment scheme in WRSNs. The performance of the energy replenishment scheme is significantly influenced by the energy level of each node, which is depends on the data collection scheme employed by the network. Consequently, integrating energy replenishment and data collection has become a new concern in WRSN research. However, the MCs’ workload and travel time increase when data collection and energy replenishment are performed simultaneously, leading to an increase in both the node’s charging delay and data collection delay. In this work, our goal is to reduce the delays in data collection and node charging by proposing a new joint energy replenishment and data collection approach. In the proposed approach, certain nodes in the network are selected as data storage nodes to temporarily store all the collected data based on their geographical locations. A special class of MCs, called MCDs (mobile charger and data collectors), is then assigned the responsibility of charging these data storage nodes and collecting the data stored. Afterwards, the task of recharging the remaining network nodes falls to another type of MC. By combining the capabilities of two distinct MC types, the workload and the travel distance of MCs are reduced. When compared to the conventional joint algorithms, the simulation results demonstrate that the proposed approach successfully decreases the delay it takes to gather data and recharge nodes. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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17 pages, 10378 KiB  

Open AccessArticle

Enhancing the Performance of Vibration Energy Harvesting Based on 2:1:2 Internal Resonance in Magnetically Coupled Oscillators

by Shakiba Dowlati, Najib Kacem and Noureddine Bouhaddi

Micromachines 2025, 16(1), 23; https://doi.org/10.3390/mi16010023 - 27 Dec 2024

Viewed by 665

Abstract

An electromagnetic vibration energy harvester with a 2:1:2 internal resonance (IR) is proposed, allowing for the simultaneous activation of two IRs within the system in order to enhance its performance in terms of bandwidth and harvested power. The device consists of three magnetically [...] Read more.

An electromagnetic vibration energy harvester with a 2:1:2 internal resonance (IR) is proposed, allowing for the simultaneous activation of two IRs within the system in order to enhance its performance in terms of bandwidth and harvested power. The device consists of three magnetically coupled oscillators separated by an adjustable gap to tune the system eigenfrequencies and achieve a 2:1:2 IR. Numerical investigations are conducted to predict the behavior of the proposed device, and a multi-objective optimization procedure is employed to enhance the harvester’s performance by introducing mass perturbations. The experimental validation of the optimized design is performed while highlighting the benefits of internal resonance, and the obtained results are in good agreement with the theoretical findings. The results indicate that incorporating two internal resonances into the harvester enhances its performance compared to the harvesters reported in the literature. The harvester achieves an ${\mathrm{SFoM}}_{\mathrm{BW}}$ of 7600 kg/m³, reflecting a high average power density over a broad bandwidth. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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15 pages, 2810 KiB  

Open AccessArticle

Generating a Full Cycle of Alternative Current Using a Triboelectric Nanogenerator for Energy Harvesting

by Aso Ali Abdalmohammed Shateri, Fengling Zhuo, Nazifi Sani Shuaibu, Rui Wan, Liangquan Xu, Dinku Hazarika, Bikash Gyawali and Xiaozhi Wang

Micromachines 2025, 16(1), 11; https://doi.org/10.3390/mi16010011 - 25 Dec 2024

Cited by 1 | Viewed by 922

Abstract

The triboelectric nanogenerator (TENG) has emerged as a promising technology for efficiently converting ambient mechanical energy into electrical energy. Among various designs, the disk-based rotational TENG has demonstrated significant potential, as it can continuously harvest energy in a sliding mode via a grating [...] Read more.

The triboelectric nanogenerator (TENG) has emerged as a promising technology for efficiently converting ambient mechanical energy into electrical energy. Among various designs, the disk-based rotational TENG has demonstrated significant potential, as it can continuously harvest energy in a sliding mode via a grating mechanism. However, horizontal mechanical energy is more common than rotational energy in many practical applications. Herein, the present study introduces a novel device: the double horizontal linear-to-rotational triboelectric nanogenerator (DHLR-TENG). This innovative approach utilizes a gear system to convert horizontal linear mechanical energy into electrical energy. The experimental results revealed that the DHLR-TENG produces a full cycle of alternating current (AC) when integrated into an electrical circuit. It consistently delivers robust performance with an open-circuit voltage of 544 V, a short-circuit current of 61.16 µA, and a maximum power output of 33.27 mW. Additionally, the device durability, capable of withstanding over 1,000,000 cycles, makes it highly effective for powering small electronic devices, such as charging capacitors and illuminating commercial LEDs. The DHLR-TENG’s versatility and efficiency mark it as a major advancement in energy harvesting, with broad implications for powering portable electronic devices in a wide range of environments. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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19 pages, 8711 KiB  

Open AccessArticle

Active Disturbance Rejection Control Based on an Improved Topology Strategy and Padé Approximation in LCL-Filtered Photovoltaic Grid-Connected Inverters

by Jinpeng Wang, Haojie Wei, Shunyao Dou, Jeremy Gillbanks and Xin Zhao

Appl. Sci. 2024, 14(23), 11133; https://doi.org/10.3390/app142311133 - 29 Nov 2024

Cited by 1 | Viewed by 684

Abstract

Although the smart grid, equipped with situational awareness and contextual understanding, represents the future of energy management and offers flexible, extensible, and adaptable intelligent grid services, it still shares similarities with traditional systems. For instance, the control performance of the DC (Direct Current) [...] Read more.

Although the smart grid, equipped with situational awareness and contextual understanding, represents the future of energy management and offers flexible, extensible, and adaptable intelligent grid services, it still shares similarities with traditional systems. For instance, the control performance of the DC (Direct Current) bus voltage will continue to be adversely affected by various uncertain interference factors in the future smart grid. In practice, this often leads to challenges, as inverters typically operate at high frequencies when connected to the grid. Therefore, the ability to effectively suppress fluctuations in DC bus voltage and mitigate their impact, as well as enhance the dynamic performance of the system, will be one of the key indicators for evaluating the upcoming smart grid. Consequently, this paper proposes DC-link Voltage Control using a two-stage Extended State Observer (ESO)-Cascaded Topology Structure in an LCL (Inductive-Capacitive-Inductive) Filtered Photovoltaic Grid-Connected Inverter based on Padé Approximation and Improved Active Disturbance Rejection Control. Results from both simulations and experiments demonstrate that the proposed algorithm performs effectively and is capable of suppressing fluctuations. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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17 pages, 5287 KiB  

Open AccessArticle

Modeling and Analyzing of CMOS Cross-Coupled Differential-Drive Rectifier for Ultra-Low-Power Ambient RF Energy Harvesting

by Liming Zheng, Hongyi Wang, Jianfei Wu, Peiguo Liu and Runze Li

Energies 2024, 17(21), 5356; https://doi.org/10.3390/en17215356 - 28 Oct 2024

Viewed by 1249

Abstract

This paper models and analyzes the Complementary Metal Oxide Semiconductor (CMOS) cross-coupled differential-drive (CCDD) rectifier for Ultra-Low-Power ambient radio-frequency energy harvesters (RFEHs) working in the subthreshold region. In this paper, two closed-form equations of CCDD rectifier output voltage and input resistance in the [...] Read more.

This paper models and analyzes the Complementary Metal Oxide Semiconductor (CMOS) cross-coupled differential-drive (CCDD) rectifier for Ultra-Low-Power ambient radio-frequency energy harvesters (RFEHs) working in the subthreshold region. In this paper, two closed-form equations of CCDD rectifier output voltage and input resistance in the subthreshold region were derived based on BSIM4 models of NMOS and PMOS. The model give insight to specify circuit parameters according to different inputs, transistor sizes, threshold voltages, numbers of stages, load conditions and compensation voltages, which can be used to optimize the rectifier circuit. There is a good agreement between the simulation results and these models, and these models have a maximum deviation of 10% in comparison with the simulation results in the subthreshold region. The measurement results of a single-stage CCDD rectifier reported in a previous paper were adopted to verify the model. The output voltage and input resistance predicted by these models provide excellent consistency with corresponding measurement results. The model can be employed to optimize the CCDD rectifier without expensive calculation in the design stage. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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23 pages, 6135 KiB  

Open AccessArticle

Assessing Stability in Renewable Microgrid Using a Novel-Optimized Controller for PVBattery Based Micro Grid with Opal-RT-Based Real-Time Validation

by Anshuman Satpathy, Rahimi Bin Baharom, Naeem M. S. Hannon, Niranjan Nayak and Snehamoy Dhar

Energies 2024, 17(20), 5024; https://doi.org/10.3390/en17205024 - 10 Oct 2024

Viewed by 1155

Abstract

This paper focuses on the distributed generation (DG) controller of a PV-based microgrid. An independent DG controller (IDGC) is designed for PV applications to improve Maximum-Power Point Tracking (MPPT). The Extreme-Learning Machine (ELM)-based MPPT method exactly estimates the controller’s reference input, such as [...] Read more.

This paper focuses on the distributed generation (DG) controller of a PV-based microgrid. An independent DG controller (IDGC) is designed for PV applications to improve Maximum-Power Point Tracking (MPPT). The Extreme-Learning Machine (ELM)-based MPPT method exactly estimates the controller’s reference input, such as the voltage and current at the MPP. Feedback controls employ linear PI schemes or nonlinear, intricate techniques. Here, the converter controller is an IDGC that is improved by directly measuring the converter duty cycle and PWM index in a single DG PV-based MG. It introduces a fast-learning Extreme-Learning Machine (ELM) using the Moore–Penrose pseudo-inverse technique and online sequential ridge methods for robust control reference (CR) estimation. This approach ensures the stability of the microgrid during PV uncertainties and various operational conditions. The internal DG control approach improves the stability of the microgrid during a three-phase fault at the load bus, partial shading, irradiance changes, islanding operations, and load changes. The model is designed and simulated on the MATLAB/SIMULINK platform, and some of the results are validated on a hardware-in-the-loop (HIL) platform. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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15 pages, 3024 KiB  

Open AccessArticle

Combining Magnetostriction with Variable Reluctance for Energy Harvesting at Low Frequency Vibrations

by Johan Bjurström, Cristina Rusu and Christer Johansson

Appl. Sci. 2024, 14(19), 9070; https://doi.org/10.3390/app14199070 - 8 Oct 2024

Viewed by 1323

Abstract

In this paper, we explore the benefits of using a magnetostrictive component in a variable reluctance energy harvester. The intrinsic magnetic field bias and the possibility to utilize magnetic force to achieve pre-stress leads to a synergetic combination between this type of energy [...] Read more.

In this paper, we explore the benefits of using a magnetostrictive component in a variable reluctance energy harvester. The intrinsic magnetic field bias and the possibility to utilize magnetic force to achieve pre-stress leads to a synergetic combination between this type of energy harvester and magnetostriction. The proposed energy harvester system, to evaluate the concept, consists of a magnetostrictive cantilever beam with a cubic magnet as proof mass. Galfenol, Fe_81.6Ga_18.4, is used to implement magnetostriction. Variable reluctance is achieved by fixing the beam parallel to an iron core, with some margin to create an air gap between the tip magnet and core. The mechanical forces of the beam and the magnetic forces lead to a displaced equilibrium position of the beam and thus a pre-stress. Two configurations of the energy harvester were evaluated and compared. The initial configuration uses a simple beam of aluminum substrate and a layer of galfenol with an additional magnet fixing the beam to the core. The modified design reduces the magnetic field bias in the galfenol by replacing approximately half of the length of galfenol with aluminum and adds a layer of soft magnetic material above the galfenol to further reduce the magnetic field bias. The initial system was found to magnetically saturate the galfenol at equilibrium. This provided the opportunity to compare two equivalent systems, with and without a significant magnetostrictive effect on the output voltage. The resonance frequency tuning capability, from modifying the initial distance of the air gap, is shown to be maintained for the modified configuration (140 Hz/mm), while achieving RMS open-circuit coil voltages larger by a factor of two (2.4 V compared to 1.1 V). For a theoretically optimal load, the RMS power was simulated to be 5.1 mW. Given the size of the energy harvester (18.5 cm³) and the excitation acceleration (0.5 g), this results in a performance metric of 1.1 mW/cm³g². Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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17 pages, 5913 KiB  

Open AccessArticle

Dynamic Analysis and Energy Harvesting Potential of Slitted Cantilever Beam Fitted with Piezoelectric Transducer

by Saad F. Almokmesh, Bashar B. Alzuwayer, Abdulrahman S. Almutairi and Abdulwahab Alhashem

Appl. Sci. 2024, 14(19), 8758; https://doi.org/10.3390/app14198758 - 28 Sep 2024

Viewed by 4002

Abstract

This research investigates how slitted beams fitted with piezoelectric transducers (PZTs) behave when generating energy from environmental vibrations. By changing slit widths, slit lengths, and tip masses, we investigated the frequency response of these beams using analytical methods and finite element analysis (FEA). [...] Read more.

This research investigates how slitted beams fitted with piezoelectric transducers (PZTs) behave when generating energy from environmental vibrations. By changing slit widths, slit lengths, and tip masses, we investigated the frequency response of these beams using analytical methods and finite element analysis (FEA). The obtained results demonstrate that resonance peaks are brought closer together, and coupling between vibrational modes is enhanced by larger slit spacing, whether or not anti-resonance dips are present, though the magnitudes of these peaks are affected by the width of the slits. The possibility of energy harvesting can be enhanced when resonance peaks are shifted and amplified by heavier tip masses. The FEA results support the analytical model, showing other characteristics such as sharp dips or anti-resonance troughs. This work provides valuable information for future design improvements by highlighting the significance of optimizing slit parameters and tip masses to enhance the efficiency of piezoelectric energy harvesters. This study demonstrates the benefits of using slitted beams with piezoelectric energy harvesting and provides recommendations for their efficient design. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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27 pages, 6323 KiB  

Open AccessReview

Current Research Status and Future Trends of Vibration Energy Harvesters

by Guohao Qu, Hui Xia, Quanwei Liang, Yunping Liu, Shilin Ming, Junke Zhao, Yushu Xia and Jianbo Wu

Micromachines 2024, 15(9), 1109; https://doi.org/10.3390/mi15091109 - 30 Aug 2024

Cited by 1 | Viewed by 4316

Abstract

The continuous worsening of the natural surroundings requires accelerating the exploration of green energy technology. Utilising ambient vibration to power electronic equipment constitutes an important measure to address the power crisis. Vibration power is widely dispersed in the surroundings, such as mechanical vibration, [...] Read more.

The continuous worsening of the natural surroundings requires accelerating the exploration of green energy technology. Utilising ambient vibration to power electronic equipment constitutes an important measure to address the power crisis. Vibration power is widely dispersed in the surroundings, such as mechanical vibration, acoustic vibration, wind vibration, and water wave vibration. Collecting vibration energy is one of the research hotspots in the field of energy. Meanwhile, it is also an important way to solve the energy crisis. This paper illustrates the working principles and recent research progress of five known methods of vibrational energy harvesting, namely, electromagnetic, piezoelectric, friction electric, electrostatic, and magnetostrictive vibrational energy harvesters. The strengths and weaknesses of each method are summarised. At the end of the article, the future trends of micro-nano vibrational energy collectors are envisioned. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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21 pages, 20532 KiB  

Open AccessArticle

A Vibrational Energy Harvesting Sensor Based on Linear and Rotational Electromechanical Effects

by Sean K. Lehman and Karl A. Fisher

Appl. Sci. 2024, 14(16), 7072; https://doi.org/10.3390/app14167072 - 12 Aug 2024

Viewed by 1206

Abstract

In this investigation, a magnetically coupled double-spring design is presented for harvesting low-level non-stationary random vibrational energy. The sensor relies on multimodal coupling between the translation and rotation of a two-spring magnet and coil system to widen the harvesting bandwidth. Energy methods are [...] Read more.

In this investigation, a magnetically coupled double-spring design is presented for harvesting low-level non-stationary random vibrational energy. The sensor relies on multimodal coupling between the translation and rotation of a two-spring magnet and coil system to widen the harvesting bandwidth. Energy methods are used to develop a model to characterize the electromechanical response of the system, the solution of which is obtained using stochastic techniques based on a particle swarm algorithm. This approach provides an efficient method to estimate system parameters that otherwise are difficult or impossible to determine with independent measurements. The experimental results demonstrate agreement with the theoretical predictions over a limited bandwidth. The sensor can effectively harvest non-stationary vibration energy down to 10⁻⁴ g within a limited bandwidth of 130–150 $\mathrm{Hz}$. The sensor prototype has an operational volume of 2.6 $\mathrm{c}{\mathrm{m}}^3$ with a calculated power density of 0.2 $\mathrm{W}/\mathrm{c}{\mathrm{m}}^3$. The sensor’s small size results in a coupling efficiency of approximately 6% across the tested bandwidth. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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15 pages, 7077 KiB  

Open AccessArticle

A Scalable, Wide-Angle Metasurface Array for Electromagnetic Energy Harvesting

by Wenping Li, Tao Shen, Binzhen Zhang and Yiqing Wei

Micromachines 2024, 15(7), 904; https://doi.org/10.3390/mi15070904 - 11 Jul 2024

Cited by 1 | Viewed by 1232

Abstract

A metasurface array for electromagnetic (EM) energy harvesting for Wi-Fi bands is presented in this paper; the metasurface array consists of a metasurface unit, a rectifier, and a load resistor. Each row of unit cells in the array is interconnected to form an [...] Read more.

A metasurface array for electromagnetic (EM) energy harvesting for Wi-Fi bands is presented in this paper; the metasurface array consists of a metasurface unit, a rectifier, and a load resistor. Each row of unit cells in the array is interconnected to form an energy transfer channel, which enables the transfer and concentration of incident power. Furthermore, at the terminal of the channel, a single series diode rectifier circuit and a load resistor are integrated in a coplanar manner. It is used to rectify the energy in Wi-Fi bands and enables DC energy harvesting across the load. Finally, a 5 × 7 prototype of the metasurface array is fabricated and measured for the verification of the rationality of the design. Testing in an anechoic chamber shows that the prototype achieves a 72% RF-DC efficiency at 5.9 GHz when the available incident power is about 7 dBm. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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13 pages, 3102 KiB  

Open AccessArticle

A Frequency Up-Conversion Piezoelectric Energy Harvester Shunted to a Synchronous Electric Charge Extraction Circuit

by Xuzhang Peng, Hao Tang, Zhongjie Li, Junrui Liang, Liuding Yu and Guobiao Hu

Micromachines 2024, 15(7), 842; https://doi.org/10.3390/mi15070842 - 28 Jun 2024

Cited by 1 | Viewed by 1195

Abstract

A frequency up-conversion piezoelectric energy harvester (FUC-PEH) consists of a force amplifier, a piezoelectric stack, a low-frequency oscillator (LFO), and a stop limiter. The force amplifier generates the amplification of stress on the piezoelectric stack. The LFO, comprising a spring and a mass [...] Read more.

A frequency up-conversion piezoelectric energy harvester (FUC-PEH) consists of a force amplifier, a piezoelectric stack, a low-frequency oscillator (LFO), and a stop limiter. The force amplifier generates the amplification of stress on the piezoelectric stack. The LFO, comprising a spring and a mass block, impacts the stop limiter during vibration to induce high-frequency oscillations within the piezoelectric stack. In this paper, we represent and simplify the FUC-PEH as a lumped-parameter model based on piezoelectric material constitutive equations and structural dynamic theories. Using the electromechanical analogy, we developed an equivalent circuit model (ECM) of the FUC-PEH. A parametric study was performed to investigate the impact of system parameters, such as spring stiffness and concentrated mass, on the FUC-PEH performance. The collision-induced amplitude truncation (AT) effect enlarges the operation bandwidth. ECM simulations show that low-frequency input excitation is converted into a high-frequency output response, enhancing the energy conversion efficiency. Furthermore, we aimed to improve the FUC-PEH’s performance using a synchronous electric charge extraction (SECE) circuit. Using the ECM approach, we established a system-level model that considers the electromechanical coupling behavior. The simulation results provide insights into the performance of FUC harvesters with SECE circuits and offer valuable design guidance. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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22 pages, 5610 KiB  

Open AccessArticle

Design of a New Supersonic Shock Wave Generator and Application in Power Generation

by Ming-Sen Hu and Uzu-Kuei Hsu

Appl. Sci. 2024, 14(12), 5074; https://doi.org/10.3390/app14125074 - 11 Jun 2024

Cited by 1 | Viewed by 1862

Abstract

Wind energy is a kind of renewable energy with great potential for development. This study mainly investigated the application of shock waves generated by high-pressure gases (wind energy) for generating energy. In this study, we designed a new supersonic shock wave generator that [...] Read more.

Wind energy is a kind of renewable energy with great potential for development. This study mainly investigated the application of shock waves generated by high-pressure gases (wind energy) for generating energy. In this study, we designed a new supersonic shock wave generator that can be reused without disassembling and assembling bolts and developed a shock wave monitoring system. It could measure the velocity of the generated shock waves at about Mach 3–5, and the output pressure exceeded 900 kg/cm² (more than 100 times the input pressure). Then, we developed a power generation system driven by supersonic shock waves based on the characteristics of the new shock wave generator, which could generate high-pressure and high-speed blast waves and could be reused. The shock wave generator can repeatedly generate high-pressure waves to drive the Tesla turbine and then rotate the magnetic energy generator for power generation. This paper used tank pressure, output pressure, gas flow, rotation speed, voltage, and current detected by the system to conduct power generation performance analysis. When the minimum rotation speed was set to 1500 rpm and three bulbs were turned on as loads, the system could generate an average voltage of 36.64 V and an average current of 211.01 mA as output (power about 7731.41 mW). Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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25 pages, 6476 KiB  

Open AccessArticle

Electro-Mechanical Coupling Analysis of L-Shaped Three-Dimensional Braided Piezoelectric Composites Vibration Energy Harvester

by Mengfei Sun, Ming Song, Gaofeng Wei and Fengfeng Hua

Materials 2024, 17(12), 2858; https://doi.org/10.3390/ma17122858 - 11 Jun 2024

Cited by 2 | Viewed by 1164

Abstract

In this article, an L-shaped three-dimensional (3D) braided piezoelectric composite energy harvester (BPCEH) is established, which consists of an elastic layer composed of a 3D braided composite, flanked by upper and lower layers of piezoelectric material and two tuning mass blocks. Glass fiber [...] Read more.

In this article, an L-shaped three-dimensional (3D) braided piezoelectric composite energy harvester (BPCEH) is established, which consists of an elastic layer composed of a 3D braided composite, flanked by upper and lower layers of piezoelectric material and two tuning mass blocks. Glass fiber and epoxy resin are used to produce a 3D braided composite. This L-shaped 3D BPCEH is mechanically designable and can be adapted to different work requirements by varying the braided angle of the 3D braided composite layer. The material parameters of 3D braided composites are predicted for different braided angles by means of a representative volume element (RVE). Electro-mechanical coupled vibration equations for the L-shaped 3D BPCEH are established. The impact of braided angles on voltage and power output is discussed in this article. Simulations using finite element method are conducted to analyze the voltage and power output responses at various braided angles. In addition, the effects of the mass of mass block B and the length of the beam on the output performance of the L-shaped 3D BPCEH are analyzed. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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15 pages, 11386 KiB  

Open AccessArticle

A Hybrid Tri-Stable Piezoelectric Energy Harvester with Asymmetric Potential Wells for Rotational Motion Energy Harvesting Enhancement

by Dawei Man, Bangdong Jiang, Yu Zhang, Liping Tang, Qinghu Xu, Dong Chen and Tingting Han

Energies 2024, 17(9), 2134; https://doi.org/10.3390/en17092134 - 30 Apr 2024

Viewed by 1131

Abstract

This paper proposes an asymmetric hybrid tri-stable piezoelectric energy harvester for rotational motion (RHTPEH). The device features an asymmetric tri-stable piezoelectric cantilever beam positioned at the edge of a rotating disk. This beam is uniquely configured with an asymmetric arrangement of magnets. Additionally, [...] Read more.

This paper proposes an asymmetric hybrid tri-stable piezoelectric energy harvester for rotational motion (RHTPEH). The device features an asymmetric tri-stable piezoelectric cantilever beam positioned at the edge of a rotating disk. This beam is uniquely configured with an asymmetric arrangement of magnets. Additionally, an elastic amplifier composed of a vertical and a rotating spring connects the beam’s fixed end and the disk. This setup enhances both the rotational amplitude and vertical displacement of the beam during motion. A comprehensive dynamical model of the RHTPEH was developed using Lagrange’s equations. This model facilitated an in-depth analysis of the system’s behavior under various conditions, focusing on the influence of key parameters such as the asymmetry in the potential well, the stiffness ratio of the amplifier springs, the radius of the disk, and the disk’s rotational speed on the nonlinear dynamic response of the system. The results show that the asymmetric hybrid tri-stable piezoelectric energy harvester makes it easier to harvest the vibration energy in rotational motion and has excellent power output performance compared with the symmetric tri-stable piezoelectric energy harvester. The output power magnitude of the system at higher rotational speeds increases as the radius of rotation expands, but when the rotational speed is low, the steady-state output power magnitude of the system is not sensitive to changes in the radius of rotation. Theoretical analysis and numerical simulations validate the effectiveness of the proposed asymmetric RHTPEH for energy harvesting in low-frequency rotating environments. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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Supplementary material:
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18 pages, 6998 KiB  

Open AccessArticle

Sustainable Composite Materials Based on Carnauba Wax and Montmorillonite Nanoclay for Energy Storage

by Serhii Brychka, Alla Brychka, Niklas Hedin and Mihail Mondeshki

Materials 2024, 17(9), 1978; https://doi.org/10.3390/ma17091978 - 24 Apr 2024

Cited by 2 | Viewed by 1571

Abstract

Sustainable composite materials, including carnauba wax, can store energy in the form of latent heat, and containing the wax may allow form-stable melting and crystallization cycles to be performed. Here, it is shown that carnauba wax in the molten state and the abundant [...] Read more.

Sustainable composite materials, including carnauba wax, can store energy in the form of latent heat, and containing the wax may allow form-stable melting and crystallization cycles to be performed. Here, it is shown that carnauba wax in the molten state and the abundant nanoclay montmorillonite form stable composites with mass ratios of 50–70% (w/w). Transmission electron microscopy analysis reveals the inhomogeneous distribution of the nanoclay in the wax matrix. Analyses with infrared and multinuclear solid-state nuclear magnetic resonance (NMR) spectroscopy prove the chemical inertness of the composite materials during preparation. No new phases are formed according to studies with powder X-ray diffraction. The addition of the nanoclay increases the thermal conductivity and prevents the leakage of the phase change material, as well as reducing the time intervals of the cycle of accumulation and the return of heat. The latent heat increases in the row 69.5 ± 3.7 J/g, 95.0 ± 2.5 J/g, and 107.9 ± 1.7 J/g for the composite materials containing resp. 50%, 60% and 70% carnauba wax. Analysis of temperature-dependent ¹³C cross-polarization solid-state NMR spectra reveal the enhanced amorphization and altered molecular dynamics of the carnauba wax constituents in the composite materials. The amorphization also defines changes in the thermal transport mechanism in the composites compared to pure wax at elevated temperatures. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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15 pages, 5359 KiB  

Open AccessArticle

Electromagnetic Energy Harvester Targeting Wearable and Biomedical Applications

by Gabriel Digregorio and Jean-Michel Redouté

Sensors 2024, 24(7), 2311; https://doi.org/10.3390/s24072311 - 5 Apr 2024

Cited by 7 | Viewed by 2677

Abstract

This work presents a miniaturized electromagnetic energy harvester (EMEH) based on two coils moving in a head-to-head permanent magnet tower. The two coils are separated by a set distance so that the applied force moves the EMEH from one equilibrium position to another. [...] Read more.

This work presents a miniaturized electromagnetic energy harvester (EMEH) based on two coils moving in a head-to-head permanent magnet tower. The two coils are separated by a set distance so that the applied force moves the EMEH from one equilibrium position to another. In this configuration, the harvester produces energy in two different working modes: when a force is applied to the moving part or when an external random acceleration is applied to the whole system. A custom test bench has been designed to characterize the behavior of this energy harvester under a variety of conditions encountered in wearable applications. Notably, at 10 Hz and 1.32 g RMS acceleration, our inertial EMEH demonstrates its capability to sustain a consistent output power of 1696 $\mathsf{\mu }$W within a total volume of 22.39 cm³, showcasing its efficiency in environments with erratic stimuli typical of wearable and biomedical applications. The presented EMEH is compared with reported inertial EMEH structures to extract its design limitations as well as future improvements, situating the present work in a comprehensive state-of-the-art and defining a generic performance target for biomedical and wearable applications. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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18 pages, 6653 KiB  

Open AccessArticle

Dynamic Flow and Heat Transfer Characteristics of Uncracked Hydrocarbon Fuel under Super-Critical Pressure in the Cooling Channel of a Regeneratively Cooled Scramjet

by Qing Xu, Guowei Lin, Haowei Li and Yaoxun Feng

Appl. Sci. 2024, 14(6), 2508; https://doi.org/10.3390/app14062508 - 16 Mar 2024

Cited by 1 | Viewed by 1173

Abstract

Regeneratively cooled scramjets are successfully used as propulsion devices in hypersonic vehicles. During operation, scramjets experience acceleration. This special process causes a dynamic flow process, and heat transfer in the cooling channel commonly occurs, which may cause hazards and control difficulties for scramjets. [...] Read more.

Regeneratively cooled scramjets are successfully used as propulsion devices in hypersonic vehicles. During operation, scramjets experience acceleration. This special process causes a dynamic flow process, and heat transfer in the cooling channel commonly occurs, which may cause hazards and control difficulties for scramjets. A dynamic numerical model with a modified heat transfer coefficient calculation method was established to study the transient flow and heat transfer processes in a cooling channel. The dynamic characteristics of the flow and heat transfer under different conditions were calculated and are discussed, including the changes in the inlet fuel mass flow, heat flux, and pressure working conditions. The results indicate that the stable time of the cooling channel outlet fuel temperature is related to the rate of change in the inlet mass flow and heat flux. The stable time of the outlet fuel temperature under decreasing heat flux working conditions was approximately 12.5 s. These results summarize the dynamic flow and heat transfer characteristics, which are significant for designing cooling channels in scramjets. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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12 pages, 3060 KiB  

Open AccessArticle

Preparation of Chitin Nanofibers and Natural Rubber Composites and Their Triboelectric Nanogenerator Applications

by Kattaliya Petchnui, Teerayut Uwanno, Mayuree Phonyiem Reilly, Chinathun Pinming, Alongkot Treetong, Visittapong Yordsri, Nutthanun Moolsradoo, Annop Klamcheun and Winadda Wongwiriyapan

Materials 2024, 17(3), 738; https://doi.org/10.3390/ma17030738 - 3 Feb 2024

Cited by 3 | Viewed by 2309

Abstract

Triboelectric nanogenerators (TENGs) have gained significant attention as promising energy-harvesting devices that convert mechanical energy into electrical energy through charge separation induced by friction and electrostatic induction. In this study, we explore the utilization of biowaste shrimp shell-extracted chitin nanofiber (ChNF) as a [...] Read more.

Triboelectric nanogenerators (TENGs) have gained significant attention as promising energy-harvesting devices that convert mechanical energy into electrical energy through charge separation induced by friction and electrostatic induction. In this study, we explore the utilization of biowaste shrimp shell-extracted chitin nanofiber (ChNF) as a viable eco-friendly material for TENG applications. Composite materials were prepared by incorporating ChNF into natural rubber (NRL) at loading levels of 0.1 and 0.2 wt% (NRL/ChNF) to form the TENG triboelectric layer. ChNFs with a uniform width of approximately 10–20 nm were successfully extracted from the shrimp shells through a simple mechanical procedure. The NRL/ChNF composites exhibited enhanced mechanical properties, as evidenced by a higher Young’s modulus (3.4 GPa) compared to pure NRL. Additionally, the NRL/ChNF composites demonstrated an increased dielectric constant of 3.3 at 0.1 MHz. Moreover, the surface potential difference of NRL increased from 0.182 V to 1.987 V in the NRL/ChNF composite. When employed as the triboelectric layer in TENG, the NRL/ChNF composites exhibited significant improvement in their output voltage, with it reaching 106.04 ± 2.3 V. This enhancement can be attributed to the increased dielectric constant of NRL/ChNF, leading to enhanced charge exchange and charge density. This study presents a straightforward and environmentally friendly technique for preparing sustainable natural materials suitable for energy-harvesting devices. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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26 pages, 7711 KiB  

Open AccessArticle

Analysis of a Wind-Driven Power Generation System with Root Slapping Mechanism

by Yi-Ren Wang, Jin-Wei Chang and Chen-Yu Lin

Appl. Sci. 2024, 14(2), 482; https://doi.org/10.3390/app14020482 - 5 Jan 2024

Viewed by 1088

Abstract

This study introduces a groundbreaking slap-type Vibration Energy Harvesting (VEH) system, leveraging a rotating shaft with magnets to induce vibrations in an adjacent elastic steel sheet through magnetic repulsion. This unique design causes the elastic sheet to vibrate, initiating the oscillation of a [...] Read more.

This study introduces a groundbreaking slap-type Vibration Energy Harvesting (VEH) system, leveraging a rotating shaft with magnets to induce vibrations in an adjacent elastic steel sheet through magnetic repulsion. This unique design causes the elastic sheet to vibrate, initiating the oscillation of a seesaw-type rigid plate lever. The lever then slaps a piezoelectric patch (PZT) at the elastic steel sheet’s root, converting vibrations into electrical energy. Notably, the design enables the PZT to withstand deformation and flapping forces simultaneously, enhancing power conversion efficiency. The driving force for the rotating shaft is harnessed from the downstream flow field generated by moving objects like rotorcraft, fixed-wing aircraft, motorcycles, and bicycles. Beyond conventional vibration energy harvesting, this design taps into additional electric energy generated by the PZT’s slapping force. This study includes mathematical modeling of nonlinear elastic beams, utilizing the Method of Multiple Scales (MOMS) for in-depth vibration mode analysis. Experimental validation ensures the convergence of theory and practice, confirming the feasibility and superior voltage generation efficiency of this slap-type VEH concept compared to traditional VEH systems. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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21 pages, 4212 KiB  

Open AccessArticle

Quasi-Zero Stiffness Vibration Sensing and Energy Harvesting Integration Based on Buckled Piezoelectric Euler Beam

by Jiying Tuo, Xiaonan Xu, Jun Li, Tianlang Dai and Zilin Liu

Sensors 2024, 24(1), 153; https://doi.org/10.3390/s24010153 - 27 Dec 2023

Cited by 1 | Viewed by 1856

Abstract

This paper presents a novel quasi-zero stiffness vibration sensing and energy harvesting integration system for absolute displacement measurements based on a buckled piezoelectric Euler beam (BPEB) with quasi-zero stiffness (QZS) characteristics. On one hand, BPEB provides negative stiffness to the system, thus creating [...] Read more.

This paper presents a novel quasi-zero stiffness vibration sensing and energy harvesting integration system for absolute displacement measurements based on a buckled piezoelectric Euler beam (BPEB) with quasi-zero stiffness (QZS) characteristics. On one hand, BPEB provides negative stiffness to the system, thus creating a vibration-free point within the system and transforming the absolute displacement measurement problem into a relative motion sensing problem. On the other hand, during the measurement process, the BPEB collects the vibration energy from the system, which can provide electrical energy for low-power relative motion sensing devices and remarkably suppress the frequency range of the jump phenomenon, thereby further expanding the frequency domain measurement range of the sensing system. The research results have shown that this system can measure the absolute motion signal of the tested object in low-frequency vibration with small excitation. By adjusting parameters such as the force–electric coupling coefficient and damping ratio, the measurement accuracy of the sensing system can be improved. Furthermore, the system can convert the mechanical energy of vibrations into electrical energy to power the surrounding low-power sensors or provide partial power. This could potentially achieve self-powering integrated quasi-zero stiffness vibration sensing, offering another approach and possibility for the automation development in wireless sensing systems and the Internet of Things field. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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20 pages, 5650 KiB  

Open AccessArticle

Research on Pneumatic Control of a Pressurized Self-Elevating Mat for an Offshore Wind Power Installation Platform

by Junguo Cui, Qi Shi, Yunfei Lin, Haibin Shi, Simin Yuan and Wensheng Xiao

Sensors 2023, 23(24), 9910; https://doi.org/10.3390/s23249910 - 18 Dec 2023

Cited by 2 | Viewed by 1544

Abstract

Efficient deep-water offshore wind power installation platforms with a pressurized self-elevating mat are a new type of equipment used for installing offshore wind turbines. However, the unstable internal pressure of the pressurized self-elevating mat can cause serious harm to the platform. This paper [...] Read more.

Efficient deep-water offshore wind power installation platforms with a pressurized self-elevating mat are a new type of equipment used for installing offshore wind turbines. However, the unstable internal pressure of the pressurized self-elevating mat can cause serious harm to the platform. This paper studies the pneumatic control system of the self-elevating mat to improve the precision of its pressure control. According to the pneumatic control system structure of the self-elevating mat, the pneumatic model of the self-elevating mat is established, and a conventional PID controller and fuzzy PID controller are designed and established. It can be seen via Simulink simulation that the fuzzy PID controller has a smaller adjustment time and overshoot, but its anti-interference ability is relatively weak. The membership degree and fuzzy rules of the fuzzy PID controller are optimized using a neural network algorithm, and a fuzzy neural network PID controller based on BP neural network optimization is proposed. The simulation results show that the overshoot of the optimized controller is reduced by 9.71% and the stability time is reduced by 68.9% compared with the fuzzy PID. Finally, the experiment verifies that the fuzzy neural network PID controller has a faster response speed and smaller overshoot, which improves the pressure control accuracy and robustness of the self-elevating mat and provides a scientific basis for the engineering applications of the self-elevating mat. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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24 pages, 11591 KiB  

Open AccessArticle

Design of an Energy Harvester Based on a Rubber Bearing Floating Slab Track

by Shuo Yu, Zheng Li, Hao Jin, Donghao Yin and Jiajia Yan

Appl. Sci. 2023, 13(22), 12287; https://doi.org/10.3390/app132212287 - 13 Nov 2023

Viewed by 1172

Abstract

It is known that a large amount of vibration mechanical energy will be generated during train operation. If the mechanical energy can be obtained from the track structure, it can greatly optimize the energy configuration of the metro. Currently, most sensors are limited [...] Read more.

It is known that a large amount of vibration mechanical energy will be generated during train operation. If the mechanical energy can be obtained from the track structure, it can greatly optimize the energy configuration of the metro. Currently, most sensors are limited to disk or cymbal structures and are not used in the track bed; different from existing structures, this paper designs a spherical energy harvester based on a rubber bearing floating slab track, wherein the size range of the spherical energy harvesting structure was approximately determined based on the geometric spatial relationships of the actual track bed internal structure. Compared to the traditional disk and cymbal energy harvesters, the mechanical and electrical properties of the spherical energy harvesting structure was studied by a numerical simulation method, and the optimal size of the spherical energy was determined by calculation. The main conclusions are as follows: (1) Compared with the traditional disk harvester and cymbal harvester, the spherical harvester had better mechanical and electrical properties. (2) By calculating the output power of energy harvesters under load matching, we found that the output power of the spherical harvester was two orders of magnitude higher than that of the disk harvester and 53% higher than that of the cymbal harvester. (3) The optimum size of the spherical harvester was when the thickness of piezoelectric layer was 2 mm, the radius was 16 mm, the axial ratio of the spherical shell was 0.4, and the thickness of the spherical shell was 4 mm. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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14 pages, 7215 KiB  

Open AccessArticle

Potential of Variable Geometry Radial Inflow Turbines as Expansion Machines in Organic Rankine Cycles Integrated with Heavy-Duty Diesel Engines

by Fuhaid Alshammari, Abdullah Alghafis, Ibrahim Alatawi, Ahmed S. Alshammari, Ahmed Alzamil and Abdullah Alrashidi

Appl. Sci. 2023, 13(22), 12139; https://doi.org/10.3390/app132212139 - 8 Nov 2023

Cited by 4 | Viewed by 1277

Abstract

This work evaluates the feasibility of utilizing an organic Rankine cycle (ORC) for waste heat recovery in internal combustion engines to meet the stringent regulations for reducing emissions resulting from the combustion of fossil fuels. The turbine is the most crucial component of [...] Read more.

This work evaluates the feasibility of utilizing an organic Rankine cycle (ORC) for waste heat recovery in internal combustion engines to meet the stringent regulations for reducing emissions resulting from the combustion of fossil fuels. The turbine is the most crucial component of the ORC cycle since it is responsible for power production. In this study, a variable geometry radial inflow turbine is designed to cope with variable exhaust conditions. A variable geometry turbine is simply a radial turbine with different throat openings: 30, 60, and 100%. The exhaust gases of a heavy-duty diesel engine are utilized as a heat source for the ORC system. Different engine operating points are explored, in which each point has a different exhaust temperature and mass flow rate. The results showed that the maximum improvements in engine power and brake specific fuel consumption (BSFC) were 5.5% and 5.3% when coupled to the ORC system with a variable geometry turbine. Moreover, the variable geometry turbine increased the thermal efficiency of the cycle by at least 20% compared to the system with a fixed geometry turbine. Therefore, variable geometry turbines are considered a promising technology in the field and should be further investigated by scholars. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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10 pages, 9758 KiB  

Open AccessFeature PaperEditor’s ChoiceArticle

Nano Groove and Prism-Structured Triboelectric Nanogenerators

by Resul Saritas, Majed Al-Ghamdi, Taylan Memik Das, Omar Rasheed, Samed Kocer, Ahmet Gulsaran, Asif Abdullah Khan, Md Masud Rana, Mahmoud Khater, Muhammed Kayaharman, Dayan Ban, Mustafa Yavuz and Eihab Abdel-Rahman

Micromachines 2023, 14(9), 1707; https://doi.org/10.3390/mi14091707 - 31 Aug 2023

Cited by 2 | Viewed by 2477

Abstract

Enhancing the output power of triboelectric nanogenerators (TENGs) requires the creation of micro or nano-features on polymeric triboelectric surfaces to increase the TENGs’ effective contact area and, therefore, output power. We deploy a novel bench-top fabrication method called dynamic Scanning Probe Lithography (d-SPL) [...] Read more.

Enhancing the output power of triboelectric nanogenerators (TENGs) requires the creation of micro or nano-features on polymeric triboelectric surfaces to increase the TENGs’ effective contact area and, therefore, output power. We deploy a novel bench-top fabrication method called dynamic Scanning Probe Lithography (d-SPL) to fabricate massive arrays of uniform 1 cm long and 2.5 µm wide nano-features comprising a 600 nm deep groove (NG) and a 600 nm high triangular prism (NTP). The method creates both features simultaneously in the polymeric surface, thereby doubling the structured surface area. Six thousand pairs of NGs and NTPs were patterned on a $6\times 5$ cm${}^2$ PMMA substrate. It was then used as a mold to structure the surface of a 200 µm thick Polydimethylsiloxane (PDMS) layer. We show that the output power of the nano-structured TENG is significantly more than that of a TENG using flat PDMS films, at 12.2 mW compared to 2.2 mW, under the same operating conditions (a base acceleration amplitude of 0.8 g). Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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19 pages, 6816 KiB  

Open AccessArticle

Design of Flexible FeCoSiB/ZnO Thin-Film Multiferroic Module for Low-Frequency Energy Harvesting

by Yan Guo, Chen Yang and Bin Huang

Energies 2023, 16(13), 5049; https://doi.org/10.3390/en16135049 - 29 Jun 2023

Cited by 2 | Viewed by 1480

Abstract

Multiphase magnetoelectric (ME) composites deposited on flexible substrates have been widely studied, which can respond to ambient mechanical, magnetic, and electric field excitations. This paper reports an investigation of flexible FeCoSiB/ZnO thin-film generators for low-frequency energy harvesting based on three substrates. Both hard [...] Read more.

Multiphase magnetoelectric (ME) composites deposited on flexible substrates have been widely studied, which can respond to ambient mechanical, magnetic, and electric field excitations. This paper reports an investigation of flexible FeCoSiB/ZnO thin-film generators for low-frequency energy harvesting based on three substrates. Both hard substrate Si and flexible substrates (Polyethylene terephthalate (PET) and Polyimide (PI)) are adopted to make a comparison of energy conversion efficiency. For the single ME laminate, a PET-based flexible ME generator presents the best ME coupling performance with an average coupling voltage output of ~0.643 mV and power output of ~41.3 nW under the alternating magnetic field of 40 Oe and 20 Hz. The corresponding ME coupling coefficient reaches the value of 321.5 mV/(cm·Oe) for this micrometer scale harvester. Flexible ME modules with double cantilevered ME generators are further designed and fabricated. When two PET-based generators are connected in series, the average voltage output and power are ~0.067 mV and ~0.447 nW, respectively. Although the energy harvested by ME thin-film generators is much smaller than bulk multiferroic materials, it proves the feasibility of using flexible FeCoSiB/ZnO generators for harvesting ambient magnetic energy and supplying sustainable electronic devices in the future. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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18 pages, 14685 KiB  

Open AccessArticle

Vibration Energy Harvester Based on Bilateral Periodic One-Dimensional Acoustic Black Hole

by Zihao Zhang, Hai Wang, Chunlai Yang, Hang Sun and Yikai Yuan

Appl. Sci. 2023, 13(11), 6423; https://doi.org/10.3390/app13116423 - 24 May 2023

Cited by 7 | Viewed by 1707

Abstract

An acoustic black hole (ABH) has been applied in the regulation of structural performance to form the aggregation effect of elastic waves in the local area of the structure, which has been used in energy harvesting in recent years. The piezoelectric vibration energy [...] Read more.

An acoustic black hole (ABH) has been applied in the regulation of structural performance to form the aggregation effect of elastic waves in the local area of the structure, which has been used in energy harvesting in recent years. The piezoelectric vibration energy harvester (VEH) integrated with the beam of a bilateral periodic 1D ABH is proposed in this study. The theoretical model of the proposed VEH is established and analyzed based on the transfer matrix method. The performance of the VEHs is numerically simulated by COMSOL Multiphysics. The simulation results show that the performance of the bilateral ABH beam is higher than its traditional counterpart. Finally, the performance of the proposed VEH is validated in an experimental system. The experimental results show that the peak output voltage of the VEH Model 3 can reach 169.16 V, which is 1.9 times that of the traditional one. In the optimal impedance matching, the output power of the third bilateral VEH is 2.7 times that of the traditional ABH, which can reach 91.52 mW. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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Supplementary material:
Supplementary File 1 (ZIP, 15423 KiB)

10 pages, 2306 KiB  

Open AccessCommunication

Improving the Output Efficiency of Triboelectric Nanogenerator by a Power Regulation Circuit

by Wenbo Li, Baichuan Leng, Shengyu Hu and Xiaojun Cheng

Sensors 2023, 23(10), 4912; https://doi.org/10.3390/s23104912 - 19 May 2023

Cited by 6 | Viewed by 3433

Abstract

Triboelectric nanogenerator (TENG) is a promising technology for harvesting energy from various sources, such as human motion, wind and vibration. At the same time, a matching backend management circuit is essential to improve the energy utilization efficiency of TENG. Therefore, this work proposes [...] Read more.

Triboelectric nanogenerator (TENG) is a promising technology for harvesting energy from various sources, such as human motion, wind and vibration. At the same time, a matching backend management circuit is essential to improve the energy utilization efficiency of TENG. Therefore, this work proposes a power regulation circuit (PRC) suitable for TENG, which is composed of a valley-filling circuit and a switching step-down circuit. The experimental results indicate that after incorporating a PRC, the conduction time of each cycle of the rectifier circuit doubles, increasing the number of current pulses in the TENG output and resulting in an output charge that is 1.6 fold that of the original circuit. Compared with the initial output signal, the charging rate of the output capacitor increased significantly by 75% with a PRC at a rotational speed of 120 rpm, significantly improving the utilization efficiency of the TENG’s output energy. At the same time, when the TENG powers LEDs, the flickering frequency of LEDs is reduced after adding a PRC, and the light emission is more stable, which further verifies the test results. The PRC proposed in this study can enable the energy harvested by the TENG to be utilized more efficiently, which has a certain promoting effect on the development and application of TENG technology. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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31 pages, 6232 KiB  

Open AccessArticle

Complex Positioning System for the Control and Visualization of Photovoltaic Systems

by Filip Žemla, Ján Cigánek, Danica Rosinová, Erik Kučera and Oto Haffner

Energies 2023, 16(10), 4001; https://doi.org/10.3390/en16104001 - 9 May 2023

Cited by 2 | Viewed by 2122

Abstract

This paper presents a proposal of a complex mechatronic system that enhances the effectivity of obtaining energy from renewable resources. The main focus is on the photovoltaic energy system, which obtains electricity from the conversion of solar radiation through photovoltaic crystalline silicon-based panels. [...] Read more.

This paper presents a proposal of a complex mechatronic system that enhances the effectivity of obtaining energy from renewable resources. The main focus is on the photovoltaic energy system, which obtains electricity from the conversion of solar radiation through photovoltaic crystalline silicon-based panels. The design of the complex mechatronic system consists of several steps. The structural design of the photovoltaic panel positioning unit in the form of a three-dimensional model is made in the selected modelling programming environment. Subsequently, a propulsion system is proposed for the designed structure, the functionality of which is verified in the programming environment Automated Dynamic Analysis of Mechanical Systems. The control system design using a programmable logical controller is also presented. The corresponding control algorithm is designed in the programming environment Step7 and covers the optimal positioning of photovoltaic panels. The developed application in the WinCC environment provides a visualization of the positioning control process. The conclusion is devoted to the assessment of the obtained results for the proposed complex mechatronic system for photovoltaic panel positioning in comparison with photovoltaic panels in fixed installation. The presented results were obtained by simulations. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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18 pages, 1637 KiB  

Open AccessArticle

Oscillating-Foil Turbine Performance Improvement by the Addition of Double Gurney Flaps and Kinematics Optimization

by Benoît Genest and Guy Dumas

Energies 2023, 16(6), 2885; https://doi.org/10.3390/en16062885 - 21 Mar 2023

Cited by 3 | Viewed by 2037

Abstract

Refinement of the performance of a fully constrained oscillating-foil turbine is carried out via the addition of passive double Gurney flaps. Flaps ranging from $h_{\mathrm{GF}}=0.005c$ to $0.075c$ are added at the trailing edge of the NACA 0015 blade [...] Read more.

Refinement of the performance of a fully constrained oscillating-foil turbine is carried out via the addition of passive double Gurney flaps. Flaps ranging from $h_{\mathrm{GF}}=0.005c$ to $0.075c$ are added at the trailing edge of the NACA 0015 blade of turbines operating in high-efficiency regimes without leading-edge vortex shedding (LEVS). Performance improvements are determined using 2D numerical simulations with an unsteady Reynolds-averaged Navier–Stokes (URANS) approach. Based on a recent study of the double Gurney flaps on stationary foils, instantaneous power-extraction coefficients are analyzed and modifications of the foil’s kinematics are tested in order to fully benefit from the Gurney flaps’ performance improvements. Modifications to the pivot point location of the foil, to the pitch-heave phase, and to the pitching amplitude of the turbine are considered. Improvements are found for all turbine cases studied, including some of the previously optimal cases reported in the literature. The double Gurney flaps, being a simple and passive device, offer great practical application potential. They represent an efficient refinement to already robust and high-performance oscillating-foil turbines operating without the perceived benefit of leading-edge vortex shedding, an essential characteristic for actual, finite-span applications. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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14 pages, 1211 KiB  

Open AccessArticle

Inverter-Less Integration of Roof-Top Solar PV with Grid Connected Industrial Drives

by M. Ryyan Khan, Intekhab Alam and M. Rezwan Khan

Energies 2023, 16(4), 2060; https://doi.org/10.3390/en16042060 - 20 Feb 2023

Cited by 3 | Viewed by 3091

Abstract

Green energy from Solar PV is getting increased attention in the industries due to the falling price of solar panels in the world market. A grid-tied inverter is one of the major components in such a system, where the DC energy from PV [...] Read more.

Green energy from Solar PV is getting increased attention in the industries due to the falling price of solar panels in the world market. A grid-tied inverter is one of the major components in such a system, where the DC energy from PV is converted to AC and synchronized with the grid to obtain power sharing between the PV and the grid for the industrial drives. In this paper, a DC link has been proposed instead of an AC link for interconnection between the solar PV system and the grid to run those industrial drives. In most modern industrial applications, induction motors are driven by VVVF (Variable Voltage and Variable Frequency) inverters to achieve efficient speed control. The inverters commonly have a rectifier section at the front end that rectifies the input AC to DC and the DC is then used in PWM mode to generate the required voltage and frequency for the induction motor operating under variable speed and load conditions. Such an inverter can use both AC or DC as the input so long the supply voltage has the right value for the inverter to operate. In our proposition, we eliminate the grid-tied inverter and use a DC link, created from the rectified AC and the regular Solar PV, to obtain the power-sharing between the PV output and the grid. Using the DC link output directly to energize the VVVF inverter has an impact on the performance of the inverter. In the proposed system, the solar PV array is designed in such a way that the grid remains as the supplementary power source only to supplement any shortfall in the PV output due to variable sunshine conditions. The control circuit used in this novel technique is inexpensive, efficient, and simple in design when compared to the grid-tied inverters. The proposed system has been implemented at Niagara Textiles in Gazipur, Bangladesh. The experimental/practical results are presented to validate the basic concept. Around a 20% reduction in the cost of energy has been reported in this paper, with a more than 90% efficient system. This will definitely make solar PV energy more competitive with regular energy and attractive to industries for its simplicity. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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19 pages, 3692 KiB  

Open AccessArticle

A Voltage Doubler Boost Converter Circuit for Piezoelectric Energy Harvesting Systems

by Abdul Haseeb, Mahesh Edla, Mustafa Ucgul, Fendy Santoso and Mikio Deguchi

Energies 2023, 16(4), 1631; https://doi.org/10.3390/en16041631 - 6 Feb 2023

Cited by 8 | Viewed by 3586

Abstract

This paper describes the detailed modelling of a vibration-based miniature piezoelectric device (PD) and the analysis modes of operation and control of a voltage doubler boost converter (VDBC) circuit to find the PD’s optimal operating conditions. The proposed VDBC circuit integrates a conventional [...] Read more.

This paper describes the detailed modelling of a vibration-based miniature piezoelectric device (PD) and the analysis modes of operation and control of a voltage doubler boost converter (VDBC) circuit to find the PD’s optimal operating conditions. The proposed VDBC circuit integrates a conventional voltage doubler (VD) circuit with a step-up DC-DC converter circuit in modes 1–4, while a non-linear synchronisation procedure of a conventional boost converter circuit is employed in modes 5–6. This integration acted as the voltage boost circuit without utilising duty cycles and complex auxiliary switching components. In addition, the circuit does not require external trigger signals to turn on the bidirectional switches. This facilitates the operation of VDBC circuit at very low AC voltage (V_ac ≥ 0.5 V). Besides this, the electrical characteristics of VDBC circuit’s input (i.e., PD) perfectly concurs with the studied testing scenarios using impedance power sources (mechanical shaker). Firstly, the proposed circuit which can rectify the PD’s output was tested at both constant input voltage with varying excitation frequency and constant excitation frequency with varying input voltage. Next, a small-scale solar battery was charged to validate the feasibility of the performance of the proposed VDBC circuit. The proposed circuit achieved a maximum output voltage of 11.7 V_dc with an output power of 1.37 mW. In addition, the rectified voltage waveform is stable due to the sminimisation of the ripples. In addition, the performance of VDBC circuit was verified by comparing the achieved results with previously published circuits in the literature. The results show that the proposed VDBC circuit outperformed existing units as described in the literature regarding output voltage and power. The developed rectifier circuit is suitable for various real-life applications such as energy harvesting and battery charging. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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25 pages, 4927 KiB  

Open AccessArticle

Enhancing the Bandwidth and Energy Production of Piezoelectric Energy Harvester Using Novel Multimode Bent Branched Beam Design for Human Motion Application

by Iresha Erangani Piyarathna, Yee Yan Lim, Mahesh Edla, Ahmed Mostafa Thabet, Mustafa Ucgul and Charles Lemckert

Sensors 2023, 23(3), 1372; https://doi.org/10.3390/s23031372 - 26 Jan 2023

Cited by 5 | Viewed by 2786

Abstract

In recent years, harvesting energy from ubiquitous ultralow-frequency vibration sources, such as biomechanical motions using piezoelectric materials to power wearable devices and wireless sensors (e.g., personalized assistive tools for monitoring human locomotion and physiological signals), has drawn considerable interest from the renewable energy [...] Read more.

In recent years, harvesting energy from ubiquitous ultralow-frequency vibration sources, such as biomechanical motions using piezoelectric materials to power wearable devices and wireless sensors (e.g., personalized assistive tools for monitoring human locomotion and physiological signals), has drawn considerable interest from the renewable energy research community. Conventional linear piezoelectric energy harvesters (PEHs) generally consist of a cantilever beam with a piezoelectric patch and a proof mass, and they are often inefficient in such practical applications due to their narrow operating bandwidth and low voltage generation. Multimodal harvesters with multiple resonances appear to be a viable solution, but most of the previously proposed designs are unsuitable for ultralow-frequency vibration. This study investigated a novel multimode design, which included a bent branched beam harvester (BBBH) to enhance PEHs’ bandwidth output voltage and output power for ultralow-frequency applications. The study was conducted using finite element method (FEM) analysis to optimize the geometrical design of the BBBH on the basis of the targeted frequency spectrum of human motion. The selected design was then experimentally studied using a mechanical shaker and human motion as excitation sources. The performance was also compared to the previously proposed V-shaped bent beam harvester (VBH) and conventional cantilever beam harvester (CBH) designs. The results prove that the proposed BBBH could harness considerably higher output voltages and power with lower idle time. Its operating bandwidth was also remarkably widened as it achieved three close resonances in the ultralow-frequency range. It was concluded that the proposed BBBH outperformed the conventional counterparts when used to harvest energy from ultralow-frequency sources, such as human motion. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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11 pages, 2218 KiB  

Open AccessArticle

Numerical Simulation on Electromagnetic Energy Harvester Oscillated by Speed Ripple of AC Motors

by Masayuki Kato

Energies 2023, 16(2), 940; https://doi.org/10.3390/en16020940 - 13 Jan 2023

Cited by 3 | Viewed by 1573

Abstract

The suppression of torque ripples in an interior permanent magnet synchronous motor (IPMSM) is essential to improve its efficiency and responsiveness. Here, we report on the development of an electromagnetic energy harvester incorporated into an IPMSM to suppress its torque ripples. The proposed [...] Read more.

The suppression of torque ripples in an interior permanent magnet synchronous motor (IPMSM) is essential to improve its efficiency and responsiveness. Here, we report on the development of an electromagnetic energy harvester incorporated into an IPMSM to suppress its torque ripples. The proposed harvester is driven to oscillations by the speed ripple of the AC motor. We derived the motion and circuit equations for the motor and the harvester according to Euler–Lagrange equations. We discussed the principle of electrical power generation and used MATLAB/Simulink numerical simulations to investigate the dynamic behavior of the proposed harvester. Our findings revealed that the active Coriolis force unnecessarily reduces the motor’s original torque, leading to unsuccessful power generation. Nevertheless, our results demonstrated that the reactive Coriolis force successfully suppresses the motor torque ripple. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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23 pages, 5808 KiB  

Open AccessReview

Towards a Highly Efficient ZnO Based Nanogenerator

by Mohammad Aiman Mustaffa, Faiz Arith, Nur Syamimi Noorasid, Mohd Shahril Izuan Mohd Zin, Kok Swee Leong, Fara Ashikin Ali, Ahmad Nizamuddin Muhammad Mustafa and Mohd Muzafar Ismail

Micromachines 2022, 13(12), 2200; https://doi.org/10.3390/mi13122200 - 12 Dec 2022

Cited by 11 | Viewed by 2875

Abstract

A nanogenerator (NG) is an energy harvester device that converts mechanical energy into electrical energy on a small scale by relying on physical changes. Piezoelectric semiconductor materials play a key role in producing high output power in piezoelectric nanogenerator. Low cost, reliability, deformation, [...] Read more.

A nanogenerator (NG) is an energy harvester device that converts mechanical energy into electrical energy on a small scale by relying on physical changes. Piezoelectric semiconductor materials play a key role in producing high output power in piezoelectric nanogenerator. Low cost, reliability, deformation, and electrical and thermal properties are the main criteria for an excellent device. Typically, there are several main types of piezoelectric materials, zinc oxide (ZnO) nanorods, barium titanate (BaTiO₃) and lead zirconate titanate (PZT). Among those candidate, ZnO nanorods have shown high performance features due to their unique characteristics, such as having a wide-bandgap semiconductor energy of 3.3 eV and the ability to produce more ordered and uniform structures. In addition, ZnO nanorods have generated considerable output power, mainly due to their elastic nanostructure, mechanical stability and appropriate bandgap. Apart from that, doping the ZnO nanorods and adding doping impurities into the bulk ZnO nanorods are shown to have an influence on device performance. Based on findings, Ni-doped ZnO nanorods are found to have higher output power and surface area compared to other doped. This paper discusses several techniques for the synthesis growth of ZnO nanorods. Findings show that the hydrothermal method is the most commonly used technique due to its low cost and straightforward process. This paper reveals that the growth of ZnO nanorods using the hydrothermal method has achieved a high power density of 9 µWcm⁻². Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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21 pages, 11755 KiB  

Open AccessArticle

Aerodynamic Performance Analysis of Trailing Edge Serrations on a Wells Turbine

by Abdullah Saad Alkhalifa, Mohammad Nasim Uddin and Michael Atkinson

Energies 2022, 15(23), 9075; https://doi.org/10.3390/en15239075 - 30 Nov 2022

Cited by 6 | Viewed by 2352

Abstract

The primary objective of this investigation was to explore the aerodynamic impact of adding trailing edge serrations to a Wells turbine. The baseline turbine consists of eight NACA 0015 blades. The blade chord length was 0.125 m and the span was 0.100 m. [...] Read more.

The primary objective of this investigation was to explore the aerodynamic impact of adding trailing edge serrations to a Wells turbine. The baseline turbine consists of eight NACA 0015 blades. The blade chord length was 0.125 m and the span was 0.100 m. Two modified serrated blade configurations were studied: (1) full-span, and (2) partial-span covering 0.288c of the trailing edge. The numerical simulations were carried out by solving the three-dimensional, incompressible steady-state Reynolds Averaged Navier-Stokes (RANS) equations using the k-ω SST turbulence model in ANSYS™ (CFX). The aerodynamic performance of the modified Wells turbine was compared to the baseline by calculating non-dimensional parameters (i.e., torque coefficient, pressure drop coefficient, and turbine efficiency). A comparison of the streamlines was performed to analyze the flow topology around the turbine blades for a flow coefficient range of 0.075 ≤ ϕ ≤ 0.275, representing an angle of attack range of 4.29° ≤ α ≤ 15.3°. The trailing edge serrations generated a substantial change in surface pressure and effectively reduced the separated flow region, thus improving efficiency in most cases. As a result, there was a modest peak efficiency increase of 1.51% and 1.22%, for the partial- and full-span trailing edge serrations, respectively. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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63 pages, 6829 KiB  

Open AccessReview

Modelling of Flow-Induced Vibration of Bluff Bodies: A Comprehensive Survey and Future Prospects

by Ying Wu, Zhi Cheng, Ryley McConkey, Fue-Sang Lien and Eugene Yee

Energies 2022, 15(22), 8719; https://doi.org/10.3390/en15228719 - 20 Nov 2022

Cited by 15 | Viewed by 4937

Abstract

A comprehensive review of modelling techniques for the flow-induced vibration (FIV) of bluff bodies is presented. This phenomenology involves bidirectional fluid–structure interaction (FSI) coupled with non-linear dynamics. In addition to experimental investigations of this phenomenon in wind tunnels and water channels, a number [...] Read more.

A comprehensive review of modelling techniques for the flow-induced vibration (FIV) of bluff bodies is presented. This phenomenology involves bidirectional fluid–structure interaction (FSI) coupled with non-linear dynamics. In addition to experimental investigations of this phenomenon in wind tunnels and water channels, a number of modelling methodologies have become important in the study of various aspects of the FIV response of bluff bodies. This paper reviews three different approaches for the modelling of FIV phenomenology. Firstly, we consider the mathematical (semi-analytical) modelling of various types of FIV responses: namely, vortex-induced vibration (VIV), galloping, and combined VIV-galloping. Secondly, the conventional numerical modelling of FIV phenomenology involving various computational fluid dynamics (CFD) methodologies is described, namely: direct numerical simulation (DNS), large-eddy simulation (LES), detached-eddy simulation (DES), and Reynolds-averaged Navier–Stokes (RANS) modelling. Emergent machine learning (ML) approaches based on the data-driven methods to model FIV phenomenology are also reviewed (e.g., reduced-order modelling and application of deep neural networks). Following on from this survey of different modelling approaches to address the FIV problem, the application of these approaches to a fluid energy harvesting problem is described in order to highlight these various modelling techniques for the prediction of FIV phenomenon for this problem. Finally, the critical challenges and future directions for conventional and data-driven approaches are discussed. So, in summary, we review the key prevailing trends in the modelling and prediction of the full spectrum of FIV phenomena (e.g., VIV, galloping, VIV-galloping), provide a discussion of the current state of the field, present the current capabilities and limitations and recommend future work to address these limitations (knowledge gaps). Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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24 pages, 5376 KiB  

Open AccessReview

Recent Advances in Energy Harvesting from the Human Body for Biomedical Applications

by Ihor Sobianin, Sotiria D. Psoma and Antonios Tourlidakis

Energies 2022, 15(21), 7959; https://doi.org/10.3390/en15217959 - 26 Oct 2022

Cited by 18 | Viewed by 6658

Abstract

Energy harvesters serve as continuous and long-lasting sources of energy that can be integrated into wearable and implantable sensors and biomedical devices. This review paper presents the current progress, the challenges, the advantages, the disadvantages and the future trends of energy harvesters which [...] Read more.

Energy harvesters serve as continuous and long-lasting sources of energy that can be integrated into wearable and implantable sensors and biomedical devices. This review paper presents the current progress, the challenges, the advantages, the disadvantages and the future trends of energy harvesters which can harvest energy from various sources from the human body. The most used types of energy are chemical; thermal and biomechanical and each group is represented by several nano-generators. Chemical energy can be harvested with a help of microbial and enzymatic biofuel cells, thermal energy is collected via thermal and pyroelectric nano-generators, biomechanical energy can be scavenged with piezoelectric and triboelectric materials, electromagnetic and electrostatic generators and photovoltaic effect allows scavenging of light energy. Their operating principles, power ratings, features, materials, and designs are presented. There are different ways of extracting the maximum energy and current trends and approaches in nanogenerator designs are discussed. The ever-growing interest in this field is linked to a larger role of wearable electronics in the future. Possible directions of future development are outlined; and practical biomedical applications of energy harvesters for glucose sensors, oximeters and pacemakers are presented. Based on the increasingly accumulated literature, there are continuous promising improvements which are anticipated to lead to portable and implantable devices without the requirement for batteries. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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14 pages, 8513 KiB  

Open AccessFeature PaperEditor’s ChoiceArticle

Scalable, Dual-Band Metasurface Array for Electromagnetic Energy Harvesting and Wireless Power Transfer

by Yiqing Wei, Junping Duan, Huihui Jing, Huimin Yang, Hao Deng, Chengwei Song, Jiayun Wang, Zeng Qu and Binzhen Zhang

Micromachines 2022, 13(10), 1712; https://doi.org/10.3390/mi13101712 - 11 Oct 2022

Cited by 15 | Viewed by 3308

Abstract

A dual-band metasurface array is presented in this paper for electromagnetic (EM) energy harvesting in the Wi-Fi band and Ku band. The array consists of metasurface unit cells, rectifiers, and load resistors. The metasurface units within each column are interconnected to establish two [...] Read more.

A dual-band metasurface array is presented in this paper for electromagnetic (EM) energy harvesting in the Wi-Fi band and Ku band. The array consists of metasurface unit cells, rectifiers, and load resistors. The metasurface units within each column are interconnected to establish two channels of energy delivery, enabling the transmission and aggregation of incident power. At the terminals of two channels, a single series diode rectifier and a voltage doubler rectifier are integrated into them to rectify the energy in the Wi-Fi band and the Ku band, respectively. A 7 × 7 prototype of the metasurface array is fabricated and tested. The measured results in the anechoic chamber show that the RF-to-dc efficiencies of the prototype at 2.4 GHz and 12.6 GHz reach 64% and 55% accordingly, when the available incident power at the surface is 3 dBm and 14 dBm, respectively. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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23 pages, 21302 KiB  

Open AccessReview

Quasi-Zero Stiffness-Based Synchronous Vibration Isolation and Energy Harvesting: A Comprehensive Review

by Zhiwen Chen, Zhongsheng Chen and Yongxiang Wei

Energies 2022, 15(19), 7066; https://doi.org/10.3390/en15197066 - 26 Sep 2022

Cited by 25 | Viewed by 4088

Abstract

In recent years, the advantages of nonlinearity in vibration isolation and energy harvesting have become increasingly apparent. The quasi-zero stiffness (QZS) of the nonlinear term provided by the negative stiffness element can achieve vibration isolation under low-frequency environments while improving the efficiency of [...] Read more.

In recent years, the advantages of nonlinearity in vibration isolation and energy harvesting have become increasingly apparent. The quasi-zero stiffness (QZS) of the nonlinear term provided by the negative stiffness element can achieve vibration isolation under low-frequency environments while improving the efficiency of energy harvesting. The QZS provides a new research idea for simultaneous vibration isolation and energy harvesting. The main purpose of this paper is to review past research results, summarize possible problems, and discuss trends. After briefly analyzing the basic principle of QZS vibration isolation, the progress of QZS in vibration isolation and energy harvesting in recent years is reviewed. At the same time, main challenges of QZS in realizing synchronous vibration isolation and energy harvesting are also discussed. Finally, according to the existing QZS challenges, the future development trend of QZS is proposed. This paper would provide a quick guide for future newcomers to this field. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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22 pages, 9643 KiB  

Open AccessArticle

Design Optimization of a Rotary Thermomagnetic Motor for More Efficient Heat Energy Harvesting

by Jonathan Hey, Maheswar Repaka, Tao Li and Jun Liang Tan

Energies 2022, 15(17), 6334; https://doi.org/10.3390/en15176334 - 30 Aug 2022

Cited by 3 | Viewed by 2499

Abstract

A rotary thermomagnetic motor that is designed for heat energy harvesting is presented in this paper. The power output, power density, and efficiency of the device is estimated using a mathematical model coupling the heat transfer, magnetic interactions, and rotor dynamics. The design [...] Read more.

A rotary thermomagnetic motor that is designed for heat energy harvesting is presented in this paper. The power output, power density, and efficiency of the device is estimated using a mathematical model coupling the heat transfer, magnetic interactions, and rotor dynamics. The design analysis shows that the efficiency of the device is maximized, when there is a balance between the volume of thermomagnetic material used against the rate of heating and cooling of the material. On the other hand, the power output is determined largely by the size of the rotor, while the power density tends to peak at a particular aspect (length to diameter) ratio of the rotor. It is also observed that a higher rate of cooling leads to more output, especially when this is matched to a similar rate of heat supplied to the thermomagnetic motor. The result from the design optimization points to an ‘optimal’ design configuration and corresponding operating conditions that results in the largest power output, highest power density and best efficiency. After the optimization, it is estimated that the rotary thermomagnetic motor is able to produce up to 88 W of power with a power density of approximately 27 kW/m³ of thermomagnetic material used, while a maximum thermal-to-mechanical energy conversion efficiency of 2.1% is achievable. The results obtained from this design analysis and optimization shows the potential for such a rotary thermomagnetic motor to be implemented at a larger scale for heat energy harvesting application. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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19 pages, 5409 KiB  

Open AccessArticle

Design of a V-Twin with Crank-Slider Mechanism Wind Energy Harvester Using Faraday’s Law of Electromagnetic Induction for Powering Small Scale Electronic Devices

by Jamshid Farzidayeri and Vishwas Bedekar

Energies 2022, 15(17), 6215; https://doi.org/10.3390/en15176215 - 26 Aug 2022

Cited by 3 | Viewed by 3350

Abstract

The maintenance of wireless sensor networks involves challenges such as the periodic replacement of batteries or energy sources in remote locations that are often inaccessible. Therefore, onboard energy harvesting solutions can provide a viable alternative. Experimental energy harvesting from fluid flow, specifically from [...] Read more.

The maintenance of wireless sensor networks involves challenges such as the periodic replacement of batteries or energy sources in remote locations that are often inaccessible. Therefore, onboard energy harvesting solutions can provide a viable alternative. Experimental energy harvesting from fluid flow, specifically from air flow, is typically restricted to a rotor and stator design or a model that strikes a piezoelectric. On the other hand, energy harvesting from mechanical vibrations routinely uses the linear motion of a magnet passing through a coil or vibrating piezoelectric elements. In this paper, we propose a novel V-twin harvester design that converts wind energy from a rotational input into the linear motion of a magnet inside a coil via a crank-slider mechanism. This design allows for high performance with a smoother voltage output when compared to a reference rotor/stator harvester design or piezoelectric method. At 0.5 Hz, a single crank-slider generated a voltage of 0.176 Vpp with an output power of 0.147 mW, whereas the reference harvester generated 0.14 mW at 1.0 Hz with a 0.432 Vpp. A single crank-slider operating at regulated frequencies of 0.5, 1, 2, and 3 Hz, with a stroke length of 50 mm and a generated continuous power of 0.147, 0.452, 2.00, and 4.48 mW, respectively. We found that under ambient wind speeds of 3.4 and 4.1 m/s the V-twin formation with the optimized configuration, in which the coils and loads were both connected in series, generated 27.0 and 42.2 mW, respectively. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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17 pages, 7831 KiB  

Open AccessArticle

An Investigation on Energy Harvesting Behavior of an Array Piezoelectric Coupled Disc Damper

by Xiangdong Xie, Xunnan Huang, Junjie Wang, Zijing Wang, Bowen Zhou and Jiankun Zhang

Micromachines 2022, 13(8), 1244; https://doi.org/10.3390/mi13081244 - 2 Aug 2022

Cited by 2 | Viewed by 1943

Abstract

In order to make full use of the vibration energy in the process of attenuating vibration, an array piezoelectric coupled disc damper is developed, which works by converting part vibration energy into electrical energy. The piezoelectric damper is made of a pair of [...] Read more.

In order to make full use of the vibration energy in the process of attenuating vibration, an array piezoelectric coupled disc damper is developed, which works by converting part vibration energy into electrical energy. The piezoelectric damper is made of a pair of piezoelectric coupled discs built in a case cylinder. Its energy harvesting behavior is studied by a series of forced-vibration experiments and simulations. The influences of some factors, such as the excitation frequency, substrate thickness, the size of the piezoelectric patch, the paste form of the piezoelectric patch and the load resistance, on the energy harvesting behavior of the damper are analyzed and concluded. The experimental results show that the maximum peak-to-peak voltage and average power from one piezoelectric patch with an inner diameter of 35 mm, an outer diameter of 80 mm, and a thickness of 1 mm can reach up to 163 V and 161 mW, respectively. This research provides a practical piezoelectric damper attenuating harmful vibration by converting them into useful electric power, and the corresponding theoretical models are derived to predict its electrical output. Full article

(This article belongs to the Topic Advanced Energy Harvesting Technology)

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