Enhancing the Performance of Human Motion Energy Harvesting through Optimal Smoothing Capacity in the Rectifier

Round 1

Reviewer 1 Report

see the attached

Comments for author File: Comments.pdf

Author Response

Comments 1: Some references can be cited to support the statement on lines 45-48 of page 2 in the introduction. These energy harvesters that can produce sufficient voltage are mostly excited by continuous input signals (such as harmonics, random), while energy harvesters that need to boost voltage mostly deal with intermittent input signals. Examples are:
- "Applying the 12 Principles of Green Engineering in Low TRL Electronics: A Case
Study of an Energy-Harvesting Platform." Sustainability 15.14 (2023): 11227.
- "Performance and dynamics of a novel bistable vibration energy harvester with
appended nonlinear elastic boundary." Mechanical Systems and Signal Processing 185
(2023): 109787.
- "Vibration energy harvester with double frequency-Up conversion mechanism for
self-Powered sensing system in smart city." Nano Energy 105 (2023): 108030.
- "Electromagnetic-triboelectric energy harvester based on vibration-to-rotation
conversion for human motion energy exploitation." Applied Energy 329 (2023):
120292.

Response 1: Thank you for suggestions. Some of the references were added to the mentioned lines as examples of harvesters, that do and do not need voltage boosting.

 

Comments 2: A full-text structure description at the end of the introduction is needed. As thus: The rest of this paper is organized as follows. In Section 2, ... In Section 3

Response 2: Thank you for pointing this out. Corresponding description was added at the end of introduction.

 

Comments 3: The comparison results of analytical model and SPICE-based simulation should be presented in one graph to more intuitively see the matching between the two (Figure 4 (a) and (b) should be merged). Besides, Figure 9 (b) and Figure 10 can also be compared in one graph.

Response 3: We agree with this comment, therefore, the corresponding figures have been updated.

 

Comments 4: It will be better to mark the horizontal coordinate "capacity C" corresponding to the peak, or point out the peak area in the figures (Figure 5,6,8,9,10).

Response 4: To improve the assessment of how well the analytical model predictions align with the various simulations and experimental results, we have updated the aforementioned graphs to visually indicate the forecasted peak locations. Exceptions are figure 9 and 10, as they were not covered by the proposed model, yet they have references to the simulations.

 

Comments 5: It is best to add the physical drawings of the experimental models in Figure 7 and Figure 9 (a).

Response 5: We appreciate your suggestion, however, we believe that the level of detail in the current schematic representations effectively conveys the essential information for our study. Yet we added a photo of the used energy management unit (Figure 7) to help visualizing the setup.

 

Comments 6: What is the significance of the analytical model presented in Section 2 for the experimental results in Section 3.2? In other words, can the experimental results in Section 3.2 be predicted by the analytical model? Perhaps a comparison between the analytical model and the experimental results for validation can illustrate this question

Response 6: As per comment 4, figures have been updated to visualize the prediction of the presented analytical model and its close matching with experimental results. Section 2 has been updated with a more conclusive graph (previously found in the Section 3) and additional explanations to better convey the impact of the model. Furthermore, we have made minor clarifications in Section 4.

 

Comments 7: Please check the whole paper, there are some typos. Examples:

- Equation (2) may be ?? = 1/2??? instead of ?? = 1/2????.

- Line 209, Page 7: "offsetting" instead of "ofsetting".

Response 7: Fixed

 

General notes: The text has multiple updates and insertions, which have been highlighted. Notable insertions can be found in lines 86–100, 177–180, 186–191, 357–362, and 367–370. Furthermore, improvements have been made to several figures to enhance the clarity and effectiveness of conveying the study's findings, specifically, Figures 3 through 8 and Figure 10.

Reviewer 2 Report

The authors have presented an Enhancing the Performance of Human Motion Energy Harvesting through Optimal Smoothing Capacity in the Rectifier. The paper is well written and investigations carried out are fine, however following need to be done before acceptance:

1. Resolution of the figures need to improve.

2. Figures are not properly aligned.

3. Authors should compare the existing model with proposed model in comparison table.

 

Good

Author Response

Comments 1: Resolution of the figures need to improve.

Response 1: Thank you for pointing this out. Figures have been updated.

 

Comments 2: Figures are not properly aligned.

Response 2: Figures were aligned by the styles given in the submission template, however, some minor enhancements have been made during this revision.

 

Comments 3: Authors should compare the existing model with proposed model in comparison table.

Response 3: The proposed and existing models operate with non-overlapping states of the input signal, making a direct comparison between them impractical. The graphical representation of one of the existing models serves primarily to illustrate the input signal's impact, and it's essential to emphasize that neither model is inherently incorrect or inferior. To address this potential confusion, we have added explanatory details in the first paragraph of Section 4.

General notes: The text has multiple updates and insertions, which have been highlighted. Notable insertions can be found in lines 86–100, 177–180, 186–191, 357–362, and 367–370. Furthermore, improvements have been made to several figures to enhance the clarity and effectiveness of conveying the study's findings, specifically, Figures 3 through 8 and Figure 10.

Reviewer 3 Report

The influence of smoothing capacitor values on rectifier output for short, intermittent signals is studied. Moreover, an analytical model that identifies an optimal smoothing capacity for the full-bridge rectifier is proposed. The paper is well organized and can be considered for publication. Here are some suggestions for the authors:

1. The forms and descriptions of human motion are not clear. Please add some explanations.

2. Please demonstrate the specific application for human motion energy harvesting, such as power supply for sensors.

3. There are some noticeable publications related to this topic of energy harvesting and vibration should be cited, such as

[1] Hybrid energy harvesting from mechanical vibrations and magnetic field, Applied Physics Letters, 2018, 113, 013901.

[2] A general electromagnetic excitation model for electrical machines considering the magnetic saturation and rub impact, Journal of Sound and Vibration, 2018, 416: 154-171.

4. Please supplement the comparisons of the proposed method and existing methods, as well as provide the shortcoming the prospect of your work.

It is oK.

Author Response

Comments 1: The forms and descriptions of human motion are not clear. Please add some explanations.

Response 1: Human motion generates sporadic bursts of power, primarily coming from slow and low-frequency movements. While there are numerous motion harvesting examples with unique generation patterns, they share the common characteristic of being short and intermittent in nature. Our study references several harvesting solutions, with one serving as the primary example (Figure 1, a). It's important to note that our main focus is on optimizing rectifiers through adjustments to smoothing capacity, a concept applicable to various signal harvesters regardless of the specific human motion involved.

 

Comments 2: Please demonstrate the specific application for human motion energy harvesting, such as power supply for sensors.

Response 2: The work focuses on optimizing one step of the power management, crucial for many energy harvesters, however, it is not about harvesting itself. Still, our introduction mentions several studies that successfully delve into the actual powering applications.

 

Comments 3: There are some noticeable publications related to this topic of energy harvesting and vibration should be cited, such as

[1] Hybrid energy harvesting from mechanical vibrations and magnetic field, Applied Physics Letters, 2018, 113, 013901.

[2] A general electromagnetic excitation model for electrical machines considering the magnetic saturation and rub impact, Journal of Sound and Vibration, 2018, 416: 154-171.

Response 3: Thank you for the suggestions, however, [1] does not cover the signals which fit the focus of our study, while [2] is not related to energy harvesting.

 

Comments 4: Please supplement the comparisons of the proposed method and existing methods, as well as provide the shortcoming the prospect of your work.

Response 4: The proposed and existing models operate with non-overlapping states of the input signal, making a direct comparison between them impractical. The graphical representation of one of the existing models serves primarily to illustrate the input signal's impact, and it's essential to emphasize that neither model is inherently incorrect or inferior. To address this potential confusion, we have added explanatory details in the Section 4, including use of computer simulation. Shortcomings in the Section 4 have also been updated.

General notes: The text has multiple updates and insertions, which have been highlighted. Notable insertions can be found in lines 86–100, 177–180, 186–191, 357–362, and 367–370. Furthermore, improvements have been made to several figures to enhance the clarity and effectiveness of conveying the study's findings, specifically, Figures 3 through 8 and Figure 10.

Round 2

Reviewer 1 Report

No comments at this phase.