Search Results (160)

This Review examines up-to-date advancements in the integration of biomolecules and solar energy technologies, with a particular focus on biohybrid photovoltaic systems. Biomolecules have recently garnered increasing interest as functional components in a wide range of solar cell architectures, since they offer a huge variety of structural, optical, and electronic properties, useful to fulfill multiple roles within photovoltaic devices. These roles span from acting as light-harvesting sensitizers and charge transport mediators to serving as micro- and nanoscale structural scaffolds, rheological modifiers, and interfacial stabilizers. In this Review, a comprehensive overview of the state of the art about the integration of biomolecules across the various generations of photovoltaics is provided. The functional roles of pigments, DNA, proteins, and polysaccharides are critically reported improvements and limits associated with the use of biological molecules in optoelectronics. The molecular mechanisms underlying the interaction between biomolecules and semiconductors are also discussed as essential for a functional integration of biomolecules in solar cells. Finally, this Review shows the current state of the art, and the most significant results achieved in the use of biomolecules in solar cells, with the main scope of outlining some guidelines for future further developments in the field of biohybrid photovoltaics. Full article

Based on the theory of optical sensing, we propose a high-precision plasmonic refractive index nanosensor, which consists of a symmetric rectangular waveguide and a circular ring containing a rectangular cavity. The designed novel tunable micro-resonant circular cavity filter based on surface plasmon excitations is able to confine light to sub-wavelength dimensions. The data show that different geometrical factors have different effects on sensing, with the geometry of the rectangular cavity and the radius of the circular ring being the key factors affecting the Fano resonance. Furthermore, the resonance bifurcation enables the structure to achieve a tunable dual Fano resonance system. The structure was tuned to obtain optimal sensitivity (S) and figure of merit values up to 3066 nm/RIU and 78. The designed structure has excellent sensing performance with sensitivities of 0.4767 nm·(mg/d${\mathrm{L}}^{-1}$) and 0.6 nm·(mg/d${\mathrm{L}}^{-1}$) in detecting Na⁺ and K⁺ concentrations in the electrolyte solution, respectively, and can be easily achieved by the spectrometer. The wavelength accuracy of 0.001 nm can be easily achieved by a spectrum analyzer, which has a broad application prospect in the field of optical integration. Full article

This study systematically investigates microplastic (MP) release from polypropylene (PP) and polylactic acid (PLA) straws across beverage matrices (deionized water, cola, and skim milk) under thermal variations. A laboratory simulation system was developed to quantify MP release at ambient temperature (25 °C) and characterize size reduction across thermal gradients (25 °C, 45 °C, and 65 °C). The integrated analytical approaches combining Fourier-transform infrared spectroscopy (FTIR), micro-FTIR, scanning electron microscopy (SEM), and optical microscopy were employed to systematically quantify and characterize MPs in terms of abundance, morphological features, and polymer composition. The findings reveal that PP straws released significantly higher MP quantities (26–28 particles/straw) than PLA counterparts (18–26 particles/straw) at 25 °C, with a pronounced burst release phase occurring within the initial 5 min of usage of straws. Thermal escalation experiments demonstrated progressive MP size reduction for both PP and PLA groups, with elevated temperatures inducing particles into smaller particles. Full article

In recent years, micro-combs, due to their compact structure and high efficiency, have proven to be a practical solution for optical sources. In this paper, an approach to flexibly modulating micro-combs is proposed, and a simulation platform based on ${\mathrm{Si}}_3{\mathrm{N}}_4$ micro-combs with highly integrated, tunable, and reconfigurable features is built. By means of the Lugiato–Lefever equation model, the dynamic evolution process of micro-combs is analyzed, and a micro-ring resonator is designed with a free spectral range of 7.24 nm, an effective mode area of $1.0829{\mu \mathrm{m}}^2$, and coherent comb lines spanning over 125 THz. Cascaded silicon nitride micro-ring filters are utilized to obtain reconfigurable modulation effects for Kerr-frequency micro-combs. Due to the significance of flexibly controlled optical sources with high-repetition rates and multiple channels for system-on-chip, our proposal has potential in photonic integrated circuit systems, such as high-density photonic computing and large-capacity optical communications, in the future. Full article

Chemotaxonomic profiling based on secondary metabolites offers a reliable approach for identifying and authenticating medicinal plants, addressing limitations associated with traditional morphological and genetic methods. Recent advances in microfluidics and nanoengineered technologies—including lab-on-a-chip systems as well as nano-enabled optical and electrochemical sensors—enable the rapid, accurate, and portable detection of key metabolites, such as alkaloids, flavonoids, terpenoids, and phenolics. Integrating artificial intelligence and machine learning techniques further enhances the analytical capabilities of these technologies, enabling automated, precise plant identification in field-based applications. Therefore, this review aims to highlight the potential applications of micro- and nanoengineered devices in herbal medicine markets, medicinal plant authentication, and biodiversity conservation. We discuss strategies to address current challenges, such as biocompatibility and material toxicity, technical limitations in device miniaturization, and regulatory and standardization requirements. Furthermore, we outline future trends and innovations necessary to fully realize the transformative potential of these technologies in real-world chemotaxonomic applications. Full article

Micro-electro-mechanical system (MEMS) electromagnetic actuators have rapidly evolved into critical components of various microscale applications, offering significant advantages including precision, controllability, high force density, and rapid responsiveness. Recent advancements in actuator design, fabrication methodologies, smart control integration, and emerging application domains have significantly broadened their capabilities and practical applications. This comprehensive review systematically analyzes the recent developments in MEMS electromagnetic actuators, highlighting core operating principles such as Lorentz force and magnetic attraction/repulsion mechanisms and examining state-of-the-art fabrication technologies, such as advanced microfabrication techniques, additive manufacturing, and innovative material applications. Additionally, we provide an in-depth discussion on recent enhancements in actuator performance through smart and adaptive integration strategies, focusing on improved reliability, accuracy, and dynamic responsiveness. Emerging application fields, particularly micro-optical systems, microrobotics, precision micromanipulation, and microfluidic components, are extensively explored, demonstrating how recent innovations have significantly impacted these sectors. Finally, critical challenges, including miniaturization constraints, integration complexities, power efficiency, and reliability issues, are identified, alongside a prospective outlook outlining promising future research directions. This review aims to serve as an authoritative resource, fostering further innovation and technological advancement in MEMS actuators and related interdisciplinary fields. Full article

The switching function of traditional waveplates necessitates mechanical replacement or the superimposition of multiple waveplates, which gives rise to a complex system and a large volume. We have devised a multifunctional micro-waveplate based on the COMSOL simulation platform (v5.6), which concurrently integrates the compact nature of metasurfaces and the dynamic regulatory features of phase-change materials. When the phase-change material is in the crystalline phase, the metasurface possesses the functionality of a half-waveplate (HWP) and is capable of performing chirality inversion of circularly polarized light within the wavelength range of 1.45 μm to 1.52 μm and 1.56 μm to 1.61 μm. When the phase-change material is in the amorphous phase, the metasurface serves as a quarter-waveplate (QWP) and can achieve the conversion between linear and circular polarization through a 90° phase delay. The phase-change metasurface breaks through the constraint of fixed functions of traditional optical waveplates, facilitating the development of optical systems towards miniaturization, intelligence, and low power consumption and providing a crucial technical route for the next generation of photonic integration and dynamic optical applications. Full article

Colloidal quantum dots (QDs) provide an ideal platform for the development of integrated optoelectronic devices due to their excellent solution processability and size-tunable optical properties. In this paper, we investigate the self-assembly process of QD micro-rings based on the solution patterning method and the lasing phenomenon in the micro-rings. The characterization of the QD micro-rings demonstrates that they possess a high-quality morphological structure and excellent optical properties. The photoluminescence spectra of the QD micro-rings with different pump fluences are studied, and photon lasing with a narrow linewidth (0.3 nm) is found to have been achieved in the micro-rings above the threshold ($23 \mathsf{\mu }\mathrm{J} \mathrm{c}{\mathrm{m}}^{-2}$). The high coherence of the lasing in the QD micro-rings is revealed by angle-resolved photoluminescence (ARPL) spectra at room temperature. Moreover, the interference pattern of the coherent lasing obtained with Young’s double-slit interference method based on the far-field Fourier optical system in the ARPL spectrum reflects the distribution of the optical field in the QD micro-rings. Our research on the self-assembly of colloidal QDs and the lasing of QD micro-rings is expected to further promote the development of on-chip integrated QD optoelectronic devices. Full article

In this paper, we present recent advancements in transmitter and receiver technologies for Optical Wireless Communication (OWC). OWC offers very wide license-free optical spectrum which enables very high capacity transmission. Additionally, beam-steered OWC is more power-efficient and more secure due to low divergence of light. One of the main challenges of OWC is wide angle transmission and reception because law of conservation of etendue restricts maximization of both aperture and field of view (FoV). On the transmitter side, we use Micro Electro-Mechanical System cantilevers activated by piezoelectric actuators together with silicon micro-lenses for narrow laser beam steering. Such design allowed us to experimentally demonstrate at least 10 Gbps transmission over 100° full angle FoV. On the receiver side, we show the use of photodiode array, and Indium-Phosphide Membrane on Silicon (IMOS) Photonic Integrated Circuit (PIC) with surface grating coupler (SGC) and array of SGC. We demonstrate FoV greater than 32° and 16 Gbps reception with photodiode array. PIC receiver allowed to receive 100 Gbps WDM with single SGC, and 10 Gbps with an array of SGC which had 8° FoV in the vertical angle and full FoV in the horizontal angle. Our results suggest that solutions presented here are scalable in throughputs and can be adopted for future indoor high-capacity OWC systems. Full article

We propose a micro-electromechanical system (MEMS)-integrated Fabry–Pérot (F–P) microcavity designed for a tunable single-photon source based on a single semiconductor quantum dot (QD). Through theoretical simulations, our design achieved a Purcell factor of 23, a photon extraction efficiency exceeding 88%, and an optical cavity mode tuning range of more than 30 nm. Experimentally, we fabricated initial device prototypes using a micro-transfer printing process and demonstrated a tuning range exceeding 15 nm. The device exhibits high mechanical stability, full reversibility, and minimal hysteresis, ensuring reliable operation over multiple tuning cycles. Our findings highlight the potential of MEMS-integrated F–P microcavities for scalable, tunable single-photon sources. Furthermore, reaching a strong coupling regime could enable efficient single-photon routing, opening new possibilities for integrated quantum photonic circuits. Full article

This article focuses on the application of digital engineering in diffractive optics for precision laser material processing. It examines methods for the development of diffractive optical elements (DOEs) and adaptive management approaches that enhance the accuracy and efficiency of laser processing. Key achievements are highlighted in numerical modeling, machine learning applications, and geometry optimization of optical systems, along with the integration of dynamic DOEs with laser systems for adaptive beam control. The discussion includes the development of complex diffractive structures with improved characteristics and new optimization approaches. Special attention is given to the application of DOEs in micro- and nanostructuring, additive manufacturing technologies, and their integration into high-performance laser systems. Additionally, challenges related to the thermal stability of materials and the complexity of adaptive DOE control are explored, as well as the role of artificial intelligence in enhancing laser processing efficiency. Full article

Aiming at the inherent nature and complexity of the influence of in-orbit micro-vibration in the imaging quality of segmented telescopes, a dynamic full-link opto-mechanical integration analysis method is proposed. The method is based on the measured micro-vibration signals of the infrared refrigerator, using the finite element method to perform the transient response analysis of the opto-mechanical system in Patran/Nastran software. The interface tool is written by Matlab to achieve the calculation of rigid body displacement and real-time data interaction with Zemax. The results show that when the working wavelength is 1 μm, the optical system has a wavefront error Root-Mean-Square value of less than 0.071λ in 4 s. Evaluating the effect of micro-vibration on the imaging quality of the system in terms of the peak ratio of the point spread function. When the exposure time was 2 s, the ratio maximum values of 0.4628 and 0.6207 were reached for the X-axis and Y-axis, respectively. The method provides an important reference basis for the evaluation of imaging quality of an optical system under micro-vibration environment with a long exposure time. Full article

This study addresses the need for a mechanical property characterization of films during Micro-Electro-Mechanical System (MEMS) processing by proposing a novel in situ on-wafer tensile strength testing method for film materials. This method integrates the film specimen with a bulk silicon test structure during fabrication, allowing for tensile strength measurements with a resolution of 0.05 MPa using only a probe and optical microscope. Utilizing this method, we successfully performed in situ on-wafer tensile strength tests on Al films of various sizes, demonstrating the impact of the process on film mechanical properties. The results validate the potential of this structure for characterizing material mechanical properties and monitoring process quality in mass production. Full article

All-optical computing is an emerging information processing technology. As a cutting-edge technology in the field of photonics, it effectively leverages the unique advantages of photons to achieve rapid computation. However, the lack of a fully functional and programmable design has slowed the progress of this type of optical computing system, especially in optical logic computing. In this paper, we design and propose a programmable photonic logic array based on all-optical computing methods. By efficiently combining on-chip photonic devices such as micro-ring resonators, we have realized a complete set of reconfigurable all-optical logic computation functions, including basic logic such as IS&NOT, AND, and OR, as well as combined logic, such as XOR and XNOR. To the best of our knowledge, the proposed architecture not only introduces three structurally similar standard logic units but also allows for their multiple-level cascading to form a large-scale photonic logic array, enabling multifunctional logic computation. Furthermore, using two independent wavelengths to represent the high and low levels of logic can effectively reduce cross-talk and overlap between signals, decreasing the dependence on the strength of the optical signal and the decision threshold. Simulation results by Photonic Integrated Circuit Simulator (INTERCONNECT) demonstrate the effectiveness and feasibility of the proposed programmable photonic logic array. Full article

This article presents advancements in using Micro-Electro-Mechanical Systemsbased (MEMS-based) devices for measuring the calorific value and hydrogen content in hydrogenated gaseous fuels, such as natural gas. As hydrogen emerges as a pivotal clean energy source, blending it with natural gas becomes essential for a sustainable energy transition. However, precise monitoring of hydrogen concentrations in gas distribution networks is crucial to ensure safety and reliability. Traditional methods like gas chromatography and mass spectrometry, while accurate, are often too complex and costly for real-time applications. In contrast, MEMS technology offers innovative, cost-effective alternatives that exhibit miniaturization, ease of installation, and rapid measurement capabilities. The article discusses the development of a novel MEMS thermal conductivity detector (TCD) and a new ionization spectrometer with an optical readout, both of which enable accurate assessment of hydrogen content and calorific values in natural gas. The TCD has demonstrated a 3% uncertainty in calorific value measurement and an impressive accuracy in determining hydrogen concentrations ranging from 2% to 25%. The research detailed in this article highlights the feasibility of integrating these MEMS devices into existing infrastructure, paving the way for efficient hydrogen monitoring in real-world applications. Moreover, preliminary findings reveal the potential for robust online process control, positioning MEMS technology as a transformative solution in the future of energy measurement. The ongoing innovations could significantly impact residential heating, industrial processes, and broader energy management strategies, facilitating a sustainable transition to hydrogen-enriched energy systems. Full article