Highly Sensitive Inertial Micro-Switch for Achieving Adjustable Multi-Threshold Acceleration
Round 1
Reviewer 1 Report
The authors propose an inertial micro-switch with multi-threshold acceleration detection capability. Mathematical and simulation model of electromechanical coupling behaviors are proposed to analyze the practicality. Moreover, the dropping system was applied to detect multi-threshold acceleration with fast response, high recoverability and repeatability. Therefore, this article can be accepted after a major revision. Detailed concerns are given below:
1. The description of time (line53, page2) seems wrong, 60s-80s is very long for circuit measurement and is conflict with below descriptions. Please check the use of units.
2. The descriptions (line170-173, page6) are conflict with figure 5, please carefully check the figure and related descriptions.
3. The unit of ordinate is wrong in figure 7, please modify it and check the whole article.
4. In figure 12, why does the amplitude change greatly over time? And what is the measure accuracy of the inertial micro-switch under such long time.
5. The applied acceleration curve is half-sine curve, what happens if using other load curves?
6. Some recent important articles should be cited in the introduction of the article. Such as Monitoring on triboelectric nanogenerator and deep learning method (DOI: 10.1016/j.nanoen.2021.106698).
Author Response
Dear Editors and Reviewers:
Thank you for your letter and for reviewers’ comments concerning our manuscript entitled “ Highly Sensitive Inertial Micro-Switch for Achieving Adjustable Multi-Threshold Acceleration ” (ID: 2150434). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in yellow in the paper. The main corrections in the paper and the responds to the reviewer’s comments are as following:
Reviewer #1:
Comment 1: The description of time (line53, page2) seems wrong, 60s-80s is very long for circuit measurement and is conflict with below descriptions. Please check the use of units.
Response: Thanks for pointing out our mistakes. We have checked that reference, and have revised units as follow: “ 60s-80s” is changed to “ 60μs-80μs”.
Comment 2: The descriptions (line170-173, page6) are conflict with figure 5, please carefully check the figure and related descriptions.
Response: Thanks for your suggestions. We have revised the description as follow: as the voltage applied to movable electrode increases from 32 V to 35 V in Figure 5, the displacement of inertial micro-switch rapidly reach to 3.5 μm and remains constant at 3.5 µm, showing pull-in voltage-32 V, high sensitivity and self-locking of inertial micro-switch.
Comment 3: The unit of ordinate is wrong in figure 7, please modify it and check the whole article.
Response: Thanks for your suggestions. We have revised the unit of ordinate in Figure 7 and then carefully corrected these mistakes like this one in this manuscript.
Comment 4: In figure 12, why does the amplitude change greatly over time? And what is the measure accuracy of the inertial micro-switch under such long time.
Response: 1) Thanks for your questions. According to the effect of g0 on threshold voltage in reference(Jufeng Deng, Yongping Hao, Shuangjie Liu, Modeling and control of threshold voltage based on pull-in characteristic for micro self-locked switch, Solid-State Electronics, 2017, 135: 85-93), the gap between dielectric layer and movable electrode is most likely the main reason for the large variation of the amplitude over time. 2) Thanks for your suggestions. The relative errors - +8.59% and -4.18%, have been added into this article, showing the measure accuracy.
Comment 5: The applied acceleration curve is half-sine curve, what happens if using other load curves?
Response: Given the mathematical model of electromechanical coupling behavior in this manuscript, multiple threshold accelerations can be sensed and regulated by controlling the voltage applied to the inertial switch, even with the use of other loading curves.
Comment 6: Some recent important articles should be cited in the introduction of the article. Such as Monitoring on triboelectric nanogenerator and deep learning method (DOI: 10.1016/j.nanoen.2021.106698).
Response: Thanks for your suggestions. Some recent important articles including “Monitoring on triboelectric nanogenerator and deep learning method” and “Simulation, fabrication and characterization of an all-metal contact-enhanced triaxial inertial microswitch with low axial disturbance”, have been added and cited in the introduction of the article.
We acknowledge reviewer’s comments and suggestions very much, which are valuable in improving the quality of our manuscript. We tried our best to improve the manuscript and made some changes in the manuscript. These changes will not influence the content and framework of the paper. And here we did not list the changes but marked in yellow in revised paper.
We appreciate for editors/reviewers’ warm work earnestly, and hope that the correction will meet with approval.
Once again, thank you very much for your comments and suggestions.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The manuscript presents a theoretical analysis and experimental results of an inertial switch for adjustable multi-threshold acceleration. Overall, the work is well presented. The following comments could be considered in the revision to make it better:
1. The title claims highly sensitive. The figure of merit to evaluate the sensitivity should be defined and discussed. How is the achieved sensitivity and comparison with the state-of-the-art devices?
2. The structure of the paper only has 3 sections. The design, fabrication and theoretical analysis are all combined into 2. Results and discussion. I suggest the author to reorganize the structure.
3. The device fabrication is presented in "2.3 Detection of multi-threshold acceleration", which is strange. Also, it's more clear and straightforward to present the fabrication process flow by showing the device in a cross-sectional view in each step.
Author Response
Dear Editors and Reviewers:
Thank you for your letter and for reviewers’ comments concerning our manuscript entitled “ Highly Sensitive Inertial Micro-Switch for Achieving Adjustable Multi-Threshold Acceleration ” (ID: 2150434). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in yellow in the paper. The main corrections in the paper and the responds to the reviewer’s comments are as following:
Reviewer #2:
Comment 1: The title claims highly sensitive. The figure of merit to evaluate the sensitivity should be defined and discussed. How is the achieved sensitivity and comparison with the state-of-the-art devices?
Response: Thanks for your suggestions. The sensitivity is evaluated by indicating the detection range of threshold acceleration, which depends on electromechanical coupling behavior in Figure 7. This mathematical model of electromechanical coupling behavior has been built to demonstrate that the multi-threshold acceleration can be sensed and adjusted by controlling the voltage applied to inertial micro-switches (line84-220, page2-8), resulting in a detection range of threshold acceleration from 500g to 2000g in 2.46ms. This detection range (500g to 2000g in 2.46ms) almost exceeds that of existing switches [2],[11],[21],[22],[32-34], demonstrating the high sensitivity of the inertial switches in this paper. To highlight the advanced nature of this inertial micro-switch, the sensitivity of inertial micro-switch is compared with that of other existing switches in the descriptions (line388-390, page14).
Comment 2: The structure of the paper only has 3 sections. The design, fabrication and theoretical analysis are all combined into 2. Results and discussion. I suggest the author to reorganize the structure.
Response: Thanks for your suggestions. According to your suggestions, the structure of this paper has been reorganized, and have consisted of five parts as followings: introduction, modeling and design, micro- fabrication of inertial micro-switch, testing and discussion, and conclusion.
Comment 3: The device fabrication is presented in "2.3 Detection of multi-threshold acceleration", which is strange. Also, it's more clear and straightforward to present the fabrication process flow by showing the device in a cross-sectional view in each step.
Response: Thanks for your suggestions. “2.3 Detection of multi-threshold acceleration” has been revised to “3. Micro-fabrication of inertial micro-switch”. Moreover, the fabrication process flow has been revised by showing the device in a cross-sectional view in each step.
We acknowledge reviewer’s comments and suggestions very much, which are valuable in improving the quality of our manuscript. We tried our best to improve the manuscript and made some changes in the manuscript. These changes will not influence the content and framework of the paper. And here we did not list the changes but marked in yellow in revised paper.
We appreciate for editors/reviewers’ warm work earnestly, and hope that the correction will meet with approval.
Once again, thank you very much for your comments and suggestions.
Author Response File: Author Response.pdf
Reviewer 3 Report
An inertial micro-switch with multi-threshold acceleration detection capability has been proposed. The results of mathematical analysis show the multi-threshold acceleration can be adjusted by controlling the voltage applied to inertial microswitches. This is a reference to improve time for outputting the acceleration signal. However, the paper should be major revised in the following areas.
1. All the parameters that appear in Formula 1 should be defined. What is h?
2. The main geometric parameters are substituted into the system-level behavioral model in ConvenorWare. Please add the correspondence mechanism between them in the paper. How to consider the internal stress of the material in the software simulation?
3. In Section 2.3, the fabrication process of the inertial microswitch should be clearly described. In line 216- 217, it is said to be fabricated according to Figure 9. But the figure is too simple to comprehend. Such as, in Line 234-235, polysilicon is used as the movable electrode. The deposition process of polysilicon is generally high temperature technology, which cannot be realized on pyrex glass substrate. The author should supplement the detailed process steps, including cross section of the process flow, fabrication methods and material thickness.
4. The deviation between the actual structure size and the design size is given In table 5,. However, the deviation of various structural parameters is extremely large, and the variation trend of the similar structure size (such as x1 and x3) is different, which is hardly explained in the MEMS process. In the general lithography and etching process, the conventional deviation is only 1-2um. It is inappropriate that the processing errors are relatively small in line 282.
5. Figure 11 shows the current-voltage curve between upper contact electrode and bottom contact electrode. Which electrode is applied 30V voltage? Please give the test schematic diagram including the test electrodes.
Author Response
Dear Editors and Reviewers:
Thank you for your letter and for reviewers’ comments concerning our manuscript entitled “ Highly Sensitive Inertial Micro-Switch for Achieving Adjustable Multi-Threshold Acceleration ” (ID: 2150434). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in yellow in the paper. The main corrections in the paper and the responds to the reviewer’s comments are as following:
Reviewer #3:
Comment 1: All the parameters that appear in Formula 1 should be defined. What is h?
Response: Thanks for your suggestions. According to reviewer’s suggestion, all of the parameters that appear in Formula have been checked and defined. h is defined as the thickness of silicon-based movable electrode.
Comment 2: The main geometric parameters are substituted into the system-level behavioral model in ConvenorWare. Please add the correspondence mechanism between them in the paper. How to consider the internal stress of the material in the software simulation?
Response: Thanks for your suggestions. According to reviewer’s suggestion, the correspondence mechanism between the system-level behavioral model and main geometric parameters has been added into this paper(line161-165, page5). The internal stress of the material in the software simulation has been shown in Figure 8 and been discussed in line210-220.
Comment 3: In Section 2.3, the fabrication process of the inertial microswitch should be clearly described. In line 216- 217, it is said to be fabricated according to Figure 9. But the figure is too simple to comprehend. Such as, in Line 234-235, polysilicon is used as the movable electrode. The deposition process of polysilicon is generally high temperature technology, which cannot be realized on pyrex glass substrate. The author should supplement the detailed process steps, including cross section of the process flow, fabrication methods and material thickness.
Response: Thanks for your suggestions. According to reviewer’s suggestion, the detailed process steps, including cross section of the process flow, fabrication methods and material thickness, have been add in this manuscript.
Comment 4: The deviation between the actual structure size and the design size is given In table 5,. However, the deviation of various structural parameters is extremely large, and the variation trend of the similar structure size (such as x1 and x3) is different, which is hardly explained in the MEMS process. In the general lithography and etching process, the conventional deviation is only 1-2um. It is inappropriate that the processing errors are relatively small in line 282.
Response: Thanks for your questions. In order to clearly elucidate the effect of manufacturing errors on the threshold voltage, we had to select a sample suitable to illustrate the effect. In this case, after comparison and analysis repeatedly, the fabrication errors of this sample in Table 5 is the best choice. Random errors are likely the main reason that some of the fabrication errors of this sample are difficult to match with the fabrication deviations of conventional lithography and etching processes. As a result, the processing errors are relatively small in line 282.
Comment 5: Figure 11 shows the current-voltage curve between upper contact electrode and bottom contact electrode. Which electrode is applied 30V voltage? Please give the test schematic diagram including the test electrodes.
Response: Thanks for your suggestions. The voltage of 30V is applied to these electrodes between movable silicon electrode and drive electrode in Figure 1(a). According to reviewer’s suggestion, the test schematic diagram including the test electrodes is added into Figure 1(a).
We acknowledge reviewer’s comments and suggestions very much, which are valuable in improving the quality of our manuscript. We tried our best to improve the manuscript and made some changes in the manuscript. These changes will not influence the content and framework of the paper. And here we did not list the changes but marked in yellow in revised paper.
We appreciate for editors/reviewers’ warm work earnestly, and hope that the correction will meet with approval.
Once again, thank you very much for your comments and suggestions.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The authors have addressed the issues I raised previously to my satisfaction and I recommend the article for publication.
