Effects of Bias Voltage and Target Current on Microstructure and Load Measurement Performance of ZnO Piezoelectric Coatings Applied to Bolt in Transformer
, Zhenbo Lan 2 and Zhuolin Xu 2,*
Round 1
Reviewer 1 Report
The article represents the original work of the authors in the area of the effects of bias voltage and target current on microstructure of ZnO piezoelectric coatings.
The topic and presented data are interesting and presented investigation is attractive.
Considering that interesting research is presented the paper should be accepted (after minor corrections).
Some suggestions to the authors:
It is usual to mention Figure in the text before its presentation. However, in the paper Figures are presented before their presentation in the text. In particular, Figure 7 shows the TOF (time of flight) but an explanation of the abbreviation is presented later.
The 17th reference is not arranged like the other references. It is underlined and the order of data is wrong.
References [18] and [19] are not mentioned in the text. It is necessary that they are also presented in the text, because each paper given in the bibliography must be cited in the text.
Line 19: … investigates on the effects …
Line 42: There should be only one point at the end.
Line 100: 10 – 3 There should be no blank space before -3.
… investigates on the effects …
Author Response
Comments 1: It is usual to mention Figure in the text before its presentation. However, in the paper Figures are presented before their presentation in the text. In particular, Figure 7 shows the TOF (time of flight) but an explanation of the abbreviation is presented later.
Reply: Thanks for your suggestion. All figures have been ranged after the section which mentioned the figures.
Comments 2:The 17th reference is not arranged like the other references. It is underlined and the order of data is wrong.
Reply: The style of Reference 17 has been corrected as that of other references.
Zhong Lin Wang，Jinhui Song，Piezoelectric Nanogenerators Based on Zinc Oxide Nanowire Arrays[J]. Science, 2006, 312（5771）: 242-246.
Comments 3: References [18] and [19] are not mentioned in the text. It is necessary that they are also presented in the text, because each paper given in the bibliography must be cited in the text.
Reply: We are so sorry for the missed citation of these two references in manuscript. Thanks for the reminder. These two references suggested that the sputtering energy of particles could greatly influence the resistance by changing the orientation and surface morphology. This could be an evidence for the phenomenon described in section 3.2. Thus, the references were cited in last sentence of this paragraph.
- Hussain, Babar, Khan, et al. Thickness uniformity and optical/structural evaluation of RF sputtered ZnO thin films for solar cell and other device applications[J]. Applied physics, A. Materials science & processing, 2017, 123(4).
- Hussain B , Khan T M . Spatial Thickness Uniformity and Structural Evaluation of RF Sputtered ZnO Thin Films for Solar Cell[J]. Conference Record of the IEEE Photovoltaic Specialists Conference, 2017.
Comments 4-6: Line 19: … investigates on the effects …
Line 42: There should be only one point at the end.
Line 100: 10 – 3 There should be no blank space before -3.
Reply: Thanks for pointing out the mistakes in our manuscript. The word “on” have been deleted. Superfluous period in Line 42 also has been deleted. The blank also has been deleted in Line 100. Also, we have carefully checked the manuscript and many similar mistakes were deleted.
Reviewer 2 Report
The article ‘Effects of bias voltage and target current on microstructure and load measurement performance of ZnO piezoelectric coatings applied for bolt in transformer’.
Thank you for the opportunity to review this paper. I read it with interest. This paper focuses on evaluating the effects of polarization current and voltage on the crystal structure and performance of piezoelectric ZnO layers (PMTS). The research and analysis was in response to a problem with bolted connections in the power industry. It was shown that the degree of crystallinity and resistance decreased as the polarization voltage increased, while the target current could increase the crystallinity. In addition, the high current caused the formation of large particles on the surface of the shell, which significantly reduced the resistance. According to the authors, the reason could be the ion energy, which affects the polarization voltage and current. The authors' optimization of the polarization voltage and current showed an increase in measurement efficiency..
The work presents a good scientific level and is written in a coherent manner, supported by the necessary literature sources. Although all the analyses seem to correctly outline the research topic, I would suggest considering making the following changes:
1. Point. 2.3 - which surface the authors consider to be the front surface - should be clarified in the text.
2. Point. 2.3 - supplement the study description with a photograph showing the method of fixing.
3. Point 3.1 - what type of current was the forcing beyond the tensile force, constant or alternating. What were the accuracy of the test apparatus.
4. Before Fig. 2 - what was the situation after the electric power was removed, were the changes permanent or reversible in some way.
5. Point 3.4 - what was the accuracy of the meter.
6. Figure 7 - the parameters of matching as well as qualitative evaluation are not very visible. I suggest the table from Fig. 7 be placed separately in the text.
7. Under Fig. 7 - what do the authors mean by '....under the optimized bias voltage of 0 V and current of 40 A'. What were the criteria for optimization and how it was carried out.
8. General remark - piezoelectric elements show their capabilities with sharp gradients in the input or result conditions - as in the application case for screw connections where a constant value of the screw state can be expected. Could this be related to current flow.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 3 Report
Recommendation Acceptance: Accept after major revision
Comment: The manuscript by Dou et al. describes effects on bias voltage and current on growth behaviors and resistance of ZnO piezoelectric sensor coating were investigated. Authors have examined the effect of morphology and structure of coatings according to the bias voltage. Also, authors have provided sufficient data by various analysis including SEM, cross-sectional SEM, and XRD. Since the authors have sufficient data and provided relevant scientific finding, I suggest the recommendation for publication in Coatings after major revision. The author should considerably clarify the following issues in order to strengthen this manuscript.
1. For the last paragraph of Introduction section, author must modify the paragraph to clearly describe the aim of the study. Therefore, please start the paragraph with the words like "Herein" or "In this study" and clearly explain the aim and scope the manuscript.
2. For the Experimental details section, there is no clear descriptions on instruments employed for analysis (such as Maker, Model, Conditions).Please add the Analysis or Instrument section or provide sufficient information in Experimental details.
3. For Figure 4, inset images of (C) is not aligned. Please check the aligns of all inset figures.
4. For Figure 3 & 6 (XRD data), author have claimed the y-axis as a. u., meaning arbitrary. Therefore, please remove the number of tick labels of y-axis.
5. For Figure 3 & 6 (XRD data), why only crystalline planes of -100 V and 40 A are only labeled? Please add the labels on all of graphs.
6. It seems like Conclusion is lacking the information of analysis data. Please add the summary of analysis results and add more scientific finding and meaning into Conclusion section.
Author Response
Reviewer 3
Comment: The manuscript by Dou et al. describes effects on bias voltage and current on growth behaviors and resistance of ZnO piezoelectric sensor coating were investigated. Authors have examined the effect of morphology and structure of coatings according to the bias voltage. Also, authors have provided sufficient data by various analysis including SEM, cross-sectional SEM, and XRD. Since the authors have sufficient data and provided relevant scientific finding, I suggest the recommendation for publication in Coatings after major revision. The author should considerably clarify the following issues in order to strengthen this manuscript.
Reply: Thanks for your work on this submitted manuscript. We are so grateful for your comments on this work. Your suggestion would be carefully considered and corresponded revision and response would be made in revised manuscript and response letter. We wish the revision could improve the quality of the manuscript.
- For the last paragraph of Introduction section, author must modify the paragraph to clearly describe the aim of the study. Therefore, please start the paragraph with the words like "Herein" or "In this study" and clearly explain the aim and scope the manuscript.
Reply: This could a good suggestion. By adding words like "Herein" or "In this study", the readability would be greatly improved and help readers to cathe the point of this work. Thus, we have added the word “in this study” in the last paragraph.
- For the Experimental details section, there is no clear descriptions on instruments employed for analysis (such as Maker, Model, Conditions).Please add the Analysis or Instrument section or provide sufficient information in Experimental details.
Reply: Thanks very much for your comments. The information related to equipment used in this work have been added in section 2
- For Figure 4, inset images of (C) is not aligned. Please check the aligns of all inset figures.
Reply: The insert images in Fig.1 and Fig.4 were aligned in the revision manuscript.. - For Figure 3 & 6 (XRD data), author have claimed the y-axis as a. u., meaning arbitrary. Therefore, please remove the number of tick labels of y-axis.
Reply: Thanks for your suggestion. We have revised the unit of the patterns by substituting a.u. with cps which means counts per second. Also, corresponded revision was made in Table 2. Similar revision was done in Fig 3 and Table 1.
- For Figure 3 & 6 (XRD data), why only crystalline planes of -100 V and 40 A are only labeled? Please add the labels on all of graphs.
Reply: Thanks for your suggestion. The peaks in mentioned graphs have been labeled.
- It seems like Conclusion is lacking the information of analysis data. Please add the summary of analysis results and add more scientific finding and meaning into Conclusion section.
Reply: Thanks for your suggestion. We have added many results with value in the conclusion. Details have been presented as below:
The resistance greatly decreased from 5.0 K Ω to 0.06 K Ω as the bias voltage increased from 0 to -100 V. Increasing the working current enhanced the orientated growth but introduced large metal particles pollution which led to the resistance decreased from 20000 to 200 K Ω. The bias voltage of 0 V and current of 40 A were beneficial for the preparation of ZnO piezoelectric sensor coatings with high resistance and c-axis preferred orientation, resulting in a high Pearson's correlation coefficient of 99.984% in monitoring a load in screw from 0 to 64 kN.
Round 2
Reviewer 3 Report
Revisions have made adequate changes have been made. Please accept as current form.
