Textile-Based Coils for Inductive Wireless Power Transmission
Round 1
Reviewer 1 Report
The focus of this paper is the development of textile coils for wireless power transmission. The work is of interest to the field of wearable sensor systems, but the authors do not make it clear in this paper why the development of textile coils is important. The introduction needs more background on the challenges wearable systems face with power transmission in order to lay the groundwork for why the results of this study are important. I think that with a clearer argument and focused re-structuring of the methods and results, this paper will be a good contribution, but in its current form it is difficult to see the contribution. The comments below go through specific parts of the paper to provide detailed feedback and area for improvement.
Line 10) The abstract in general needs more specific on the study design and results. In this line, it is stated that “textile-based coils will be examined and evaluated…” It’s unclear if this investigation is part of this paper or not.
Line 21) Remove comma after “estimates”
Lines 23-24) Citations to other works are necessary to legitimize these statements.
Line 26) Sentence starting with “For example”: This is not a complete sentence and should be attached to the previous sentence.
Line 30) Many statements are made about textile components without any references to existing literature. Such references should be incorporated here.
Line 31) This first paragraph should really build the argument for why wireless power transmission helps solve some of the stated issues, building the argument for the work presented in this paper.
Lines 41-54) What was missing from this work that you hope to address in this research study? When referencing the work of others, it is important to put it in perspective with the work you've done to show how you are building on the literature.
Lines 55-60) Same comment here; why is this information important and how does it relate to your work? Overall, the introduction lacks a clear and logical argument for why you've done this work.
Line 63) This should also be stated somewhere in the introduction to help guide the argument of the paper.
Line 77) “Due to its high fineness”: Is the problem that it breaks during manufacture with a machine? Would be good to clarify what this means.
Line 110) Why isn't this paste listed or shown in the table of materials? I also don't think these separated bullet points are really necessary.
Line 113) Does “rough structure” mean the threads are too thick for the machine? Would be good to clarify what the implications of the rough structure are.
Figure 1) Is there a risk of contact between the rows during movement? Was this investigated? Worth mentioning, given how closely wrapped the coils appear to be in the images.
Lines 148-149) This statement belongs more in the discussion section than here.
Table 1) Would like to see this shown earlier with a clear description of the experimental design from the outset. This would ensure that each new set of coils is expected and doesn't come as a surprise to the reader.
Figures) There are some formatting issues for several of the figures. Caption should appear below instead of to the right.
Line 190) Missing a space “Figure5”
Figure 6) The quality of these images and formatting of this figure could be improved to enhance understanding.
Lines 210-211) Several words in this sentence don't make sense. "qualify" and "realization" might not be the words you're looking for; it's hard to understand what this statement means.
Lines 213-216) The description of the coupling and quality factors should be more concise. It would be helpful to describe the calculation of these metrics before going into the details of the experimental setup and challenges there.
Figure 7) Not sure that the picture of the transmitter coil adds anything to the reader’s understanding.
Line 238) It is not very clear what the measurements actually are here. Could use a more detailed explanation.
Line 268) This statement does not make sense.
Line 299) The word “anyway” is not generally considered to be professional language.
Discussion) At this point in the paper, it still has not been explained why integrating these induction coils into textiles is important or beneficial for wearable sensor systems. This argument is important to introduce in the beginning of the paper and return to here in the discussion.
Line 319) How do we know if this is good enough for a certain application? Can these textile coils replace traditional systems with performance like this?
Line 328) The wording of this eddy current statement is confusing.
Lines 330-331) What does this mean exactly? There is contact within the coil?
Lines 332-337) I do not understand this section. Why wasn't it known whether inductance or capacitance was being measured? And what does it mean to say that measurement of impedance would be senseless?
Line 342) Assuming "it" refers to insulation?
Line 349) “power electronic”: Not sure what this phrase means.
Line 353) Should be “compares” instead of “compare”
Lines 356-358) Give specifics on which systems these textile coils are usable in, if there are any.
Lines 360) “there is a lot of variation”: This does not seem like the correct reason. Variation in resistance should be measurable; do you mean there is variation with the added presence of capacitance?
Line 367) What is this final application? Should be more explicit about the potential benefits of textile coils when applied to specific systems.
Author Response
Dear Reviewer,
Thank you very much for reviewing our manuscript “Textile Based Coils for Inductive Wireless Power Transmission” and the opportunity to resubmit a revised copy of the manuscript. We highly appreciate the interest that you have taken in our manuscript, the complimentary comments and the constructive criticism. We would also like to take this opportunity to express our thanks for your careful and constructive review. Based on the comments, we have made changes of the manuscript, which are detailed below.
We have carefully gone through the comments and tried our best to respond to them. Now we believe this resulted in an improved revised manuscript. In the revised manuscript the changes made are highlighted in red.
We hope that you find our responses satisfactory and that the manuscript is now acceptable for publication.
Best regards,
Sebastian Micus
Author Response File: 
Author Response.docx
Reviewer 2 Report
Dear Authors,
the paper is interesting and deals with the hot topic of wireless power transfer for wearable devices. My comments focus mainly on the aspects of your work related to measurements and circuit theory. The work on these points is a bit confused, for what it is not clear which equivalent circuit was used, the quality of the measurement setup and instrumentation, etc.
In addition, results should be put in graphical form to show the location on a frequency/quality/efficiency plane of the tested coils.
1) Line 21. Sentence should be in the past because the period has almost expired.
2) Line 41. Reference missing after "Sun et al.". Same for "Li" at line 55.
3) Line 113. "Most" is better than "more".
4) Line 148 and following. You mention coil size and coupling, but there are no quantitative references for applications that represent constraints and requirements for your devices. You should introduce at the beginning typical size and coupling values, including other electrical parameters, with reference to existing realizations documented in the literature.
5) Line 211. Correct "we will to ..."
6) Line 214. "penetrates" is not a correct term.
7) Line 216-217. What is the relationship between "do not provide info about losses" and favours energy transfer". Improve quality of sentences between line 215 ad 220, and quantify your parameters: coupling quality, transmission quality, etc.
8) Line 251. Transmission quality is indicated with the typical notation of a factor of merit. Please, for all these quantities (e.g. transmission quality and efficiency) give an equivalent circuit of the setup and application, so it is clear what z11, z22, etc refer to. Please, also define and justify these quantities with reference to circuit theory to describe the behavior of the equivalent circuit.
9) Table 6 and elsewhere in sec. 3. To better describe the behavior of a copper and textile coil, please, include the resistance of the coil and the expected skin effect, if relevant.
10) Line 302-303. You mention the measurement of inductance and capacitance, that however are not reported nor shown in an equivalent circuit. Please, give details of the measurement technique and accuracy, and how the electrical parameters are determined, and how the z quantities are calculated to finally determine Q and eta.
11) References to put in MDPI style.
12) General. Could you provide metrological characterization in terms of measurement errors, accuracy, uncertainty?
Author Response
Dear Reviewer,
Thank you very much for reviewing our manuscript “Textile Based Coils for Inductive Wireless Power Transmission” and the opportunity to resubmit a revised copy of the manuscript. We highly appreciate the interest that you have taken in our manuscript, the complimentary comments and the constructive criticism. We would also like to take this opportunity to express our thanks for your careful and constructive review. Based on the comments, we have made changes of the manuscript, which are detailed below.
We have carefully gone through the comments and tried our best to respond to them. Now we believe this resulted in an improved revised manuscript. In the revised manuscript the changes made are highlighted in red.
We hope that you find our responses satisfactory and that the manuscript is now acceptable for publication.
Best regards,
Sebastian Micus
Author Response File: Author Response.docx
Reviewer 3 Report
This is a topic research by many in association with wearable electronics. the particular research reported in this paper represents an effort to clarify the efficiency of textile based coils for inductive wireless power transmission.
- The introduction argued for the necessity of the research, but the literature review was not carried out as widely as it should be. In addition, no critical comments were made to the literatures reviewed, and no research focus was identified. There is no mentioning of the aims and objectives of the work, and the research strategy was not spelt out clearly.
- The Conclusions section was written as a mixture of discussions and conclusions, which need to be revised. The discussion elements should go to the Discussions section. the conclusions should be made concise and clear to reflect the achievements and findings from the work.
Author Response
Dear Reviewer,
Thank you very much for reviewing our manuscript “Textile Based Coils for Inductive Wireless Power Transmission” and the opportunity to resubmit a revised copy of the manuscript. We highly appreciate the interest that you have taken in our manuscript, the complimentary comments and the constructive criticism. We would also like to take this opportunity to express our thanks for your careful and constructive review. Based on the comments, we have made changes of the manuscript, which are detailed below.
We have carefully gone through the comments and tried our best to respond to them. Now we believe this resulted in an improved revised manuscript. In the revised manuscript the changes made are highlighted in red.
We hope that you find our responses satisfactory and that the manuscript is now acceptable for publication.
Best regards,
Sebastian Micus
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
Dear Authors,
thank you for your replies and amendments. The major weakness I see is related to previous comment 10) and the request to clarify the circuit parameters and equivalent circuit. I expand i the following previous comment 10.
10a) You have indicated your ref [13] and you have not reported any equivalent circuit, nor explained how the equivalent circuit with ports 1 and 2 of ref [13] maps onto your test setup.
10b) It is remarked that ref [13] is in German, so not so accessible to many. You would better add a reference in English.
10c) You have replied that you measure only resistance, so it is not clear how you can calculate the Z11, Z12, etc. in your eq (1).
10d) When you report Q and eta , although they are taken from an external ref (in this case [13]), you should introduce them explaining why you take these parameters as significant and how they are interpreted to rank the results and
10e) Regarding the explanation provided so far, I quote your lines 208-211: "The transmission quality is a system parameter that can be determined metrologically and analytically and it enables an objective comparison of different systems. It indicates the efficiency which can be achieved under ideal conditions. It also provides information about the drop-in efficiency with variable load resistance."
As you see you have said very little that is accurate and quantitative: "metrologically" and you measure only resistance, but then you get all the values in q (1) somehow; "comparison", but I do not see the criteria to establish what are the minimum requirements, and when a difference in value is significant; "variable load resistance", but you should give an equivalent circuit where it is clear how Q and eta are interpreted and the mutual relationship with this load resistance.
New comment 20) : please, revise your ref [15] with link, that is a google search link. After search I have identified http://gbtp.or.kr/wireless_eng/upload//20171110025634271.pdf and https://www.wirelesspowerconsortium.com/data/downloadables/2/2/0/5/qi-wireless-power-specification-non-confidential.zip. Please, also clarify in the 309 pages of the Qi spec Part 4 what is the section/page you use, unless it is really evident.
Author Response
Dear Reviewer,
Thank you very much for reviewing our manuscript “Textile Based Coils for Inductive Wireless Power Transmission” and the opportunity to resubmit a revised copy of the manuscript. We highly appreciate the interest that you have taken in our manuscript, the complimentary comments and the constructive criticism. We would also like to take this opportunity to express our thanks for your careful and constructive review. Based on the comments, we have made changes of the manuscript, which are detailed below.
We have carefully gone through the comments and tried our best to respond to them. Now we believe this resulted in an improved revised manuscript. In the revised manuscript the changes made are highlighted in red.
We hope that you find our responses satisfactory and that the manuscript is now acceptable for publication.
Best regards,
Sebastian Micus
Author Response File: Author Response.docx
Round 3
Reviewer 2 Report
Dear Authors,
thank you for your additional explanations and the implementation in the manuscript. No other comments on my side.
