Experimental and Numerical Investigation of Resonance Characteristics of Novel Pumping Element Driven by Two Piezoelectric Bimorphs
Round 1
Reviewer 1 Report
This paper presents resonance characteristics of a two pumping element by using piezoelectric bimorphs. The manuscript is written very well and it includes interesting findings from experimental and numerical approaches. For completeness of the paper, authors are requested to revise the following points.
1. There is no unit for lengths in Figure 2.
2. Why mode 3 did not appear in the AF-ESPI experiment ? Its reason must be discussed in the paper.
3. Modes 6 and 8 did not appear in Figure 8. Modes 3, 5, 6 and 8 did not appear in Figure 9. These results have no correspondence with the description in the 247th line.
4. The readers are interested in the pumping performance. How amount the air or water transported by the new pumping element? Which mode is better for pumping?
Author Response
The revised version of the manuscript has been made according to the comments of reviewerw #1, 2, 3, and 4.We are very grateful to their valuable comments which improve the quality of the paper. We mark up the corrections and changes in the revised manuscript with a yellow highlight to locate the modifications. The main revision of the manuscript and responses to the review comment are summarized as follows.
Reviewer’s comments for the revised manuscript
A. Responses to the review comments for reviewer #1
English language and style
( ) Extensive editing of English language and style required
( ) Moderate English changes required
(x) English language and style are fine/minor spell check required
( ) I don't feel qualified to judge about the English language and style
This paper presents resonance characteristics of a two pumping element by using piezoelectric bimorphs. The manuscript is written very well and it includes interesting findings from experimental and numerical approaches. For completeness of the paper, authors are requested to revise the following points.
Response:
The Authors thank to reviewer’s comments. The point-to-point comments revise as the following.
A1. Comment: There is no unit for lengths in Figure 2.
Response:
The scale of pumping elements is the same with piezoelectric bimorph as shown in Figures 1 and 2. We add the “unit in mm” in the revised Figure 2. Thanks for reviewer reminding
Revise:
Please see the revised Figure 2.
A2. Comment: Why mode 3 did not appear in the AF-ESPI experiment? Its reason must be discussed in the paper.
Response:
Since there are two bimorphs vibrating in the small space (the distance between the two plates is very small), and the frequencies of mode 3 and 4 are relatively close, the mode shapes will be affected by both the interactions between two bimorphs and two modes. It is also indicated in the impedance variation curve that the in-plane motion of mode 4 is relatively large compared to other modes, hence the in-plane displacement of mode 4 may obstruct the reveal of mode 3. The authors revised the explanation in the manuscript in various sections.
Revise:
Please see the 3rd paragraph in “Section 3. Experimental and Numerical Results”.
In the air-coupled case, mode 3 did not appear in the AF-ESPI experiment below 6 kHz. …… The mode 3 cannot be measured by ESPI, as shown in Figure 8, that might be since there are two bimorphs vibrating in the small space (the distance between the two plates is very small), and the frequencies of mode 3 and 4 are relatively close. The mode shapes will be affected by both the interactions between two bimorphs and two modes. The similar reason might explain for modes 5, 6, and mode 7, 8 in the water-coupled case as shown in Figure 9. However, the more vibration modes did not appear in glycerine-coupled case as shown in Figure 10, since the fluid property of glycerine might be influenced on the more dramatic for piezoelectric elements.
Please see the last 3rd paragraph in “Section 3. Experimental and Numerical Results”.
Figures 14-16 respectively present the impedance variation curves (anti-phase and in-phase motion) obtained under air-coupled, water-coupled, and glycerine-coupled conditions. It is also indicated in the impedance variation curve, as shown in Figure 14, that the in-plane motion of mode 4 (1636 Hz in FEM) is relatively large compared to other modes, hence the in-plane displacement of mode 4 may obstruct the reveal of mode 3 (1363 Hz in FEM). …...
A3. Comment: Modes 6 and 8 did not appear in Figure 8. Modes 3, 5, 6 and 8 did not appear in Figure 9. These results have no correspondence with the description in the 247th line.
Response:
It is wrong description. The revision has been modified and thanks for reviewer.
Revise:
Please see the 3rd paragraph in “Section 3. Experimental and Numerical Results”.
In the air-coupled case, mode 3 did not appear in the AF-ESPI experiment below 6 kHz. Modes 6, 8 and modes 3, 5, 6, 8 did not appear in the water-coupled and glycerine-coupled cases, respectively. In the water-coupled case, mode 3 appeared in the AF-ESPI measurements. ……
A4. Comment: The readers are interested in the pumping performance. How amount the air or water transported by the new pumping element? Which mode is better for pumping?
Response:
The reader is truly interested in the efficiency of pump, especially for the good performance of vibration mode. The revision has clearly indicated on these modes in anti-phase vibration.
Revise:
Please see the 3rd paragraph in “Section 3. Experimental and Numerical Results”.
The results of the flow rate and the flow velocity of the pumping element for anti-phase and in-phase vibration are listed in Table 6(a)-(b) and Table 7(a)-(b). As indicated in these data, both the gain of flow rate and the flow velocity increment are larger for anti-phase than for in-phase vibration. For both average flow rate and velocity, the efficiency of low frequencies (1st modes to 3rd mode; that is, 20 Hz, 170 Hz, and 490 Hz) in anti-phase vibration is better as shown in Tables 6 and 7 because of the larger displacement.. ……
Author Response File: 
Author Response.pdf
Reviewer 2 Report
This manuscript presents a performance characteristic of micro-pump generated by two layers of piezoelectric bimorphs. The manuscript is well organized and written. However, some sentences should be revised in term of English.
The resonance frequency is measured by ESPI, LVD and impedance analysis method and it is compared to numerical analysis. As the authors emphasize, the flow velocity is increased compared to single bimorphs.
minor issues:
1. If possible, arrange and resize the Figure. 6 (a) and the (b) as the same size.
2. The final results (Table 6 ~ 8) can be depicted as figures for the readers understanding.
3. As the main subject of this manuscript, comparisons of single and two layers of bimorph should be done intensively.
Author Response
Response to the review Comments on the manuscript
“Experimental and Numerical Investigation of Resonance Characteristics of Novel Pumping Element Driven by Two Piezoelectric Bimorphs”
(Manuscript No.: applsci-471529)
Yu-Chih Lin, Yu-Hsi Huang*, and Kwen-Wei Chu
The revised version of the manuscript has been made according to the comments of reviewerw #1, 2, 3, and 4.We are very grateful to their valuable comments which improve the quality of the paper. We mark up the corrections and changes in the revised manuscript with a yellow highlight to locate the modifications. The main revision of the manuscript and responses to the review comment are summarized as follows.
Reviewer’s comments for the revised manuscript
B. Responses to the review comments for reviewer #2
English language and style
( ) Extensive editing of English language and style required
( ) Moderate English changes required
(x) English language and style are fine/minor spell check required
( ) I don't feel qualified to judge about the English language and style
Yes | Can be improved | Must be improved | Not applicable | |
Does the introduction provide sufficient background and include all relevant references? | ( ) | (x) | ( ) | ( ) |
Is the research design appropriate? | (x) | ( ) | ( ) | ( ) |
Are the methods adequately described? | (x) | ( ) | ( ) | ( ) |
Are the results clearly presented? | (x) | ( ) | ( ) | ( ) |
Are the conclusions supported by the results? | ( ) | (x) | ( ) | ( ) |
Comments and Suggestions for Authors
This manuscript presents a performance characteristic of micro-pump generated by two layers of piezoelectric bimorphs. The manuscript is well organized and written. However, some sentences should be revised in term of English.
The resonance frequency is measured by ESPI, LVD and impedance analysis method and it is compared to numerical analysis. As the authors emphasize, the flow velocity is increased compared to single bimorphs.
Response: English should be polished before re-submission.
The paper has been edited by native speaker to polish the English in this revised version. Most of text in manuscript has been revised by editor and make up with a yellow highlight to locate the important modifications. The reacceptance is attached as following text. The minor issues are revised as the following.
Revise:
English Editing Certificate
This hereby certifies that the paper (Experimental and Numerical Investigation of Resonance Characteristics of Novel Pumping Element Driven by Two Piezoelectric Bimorphs) authored by Yu-Chih Lin, Yu-Hsi Huang, and Kwen-Wei Chu has been duly edited and proofread by the editing staff at Acceptediting on November 9, 2018. The document has been checked and improved with regard to grammar, punctuation, spelling, verb usage, sentence structure, conciseness, readability, and writing style.
Michael D. Ash
Chief Editor, Acceptediting
Tel: +886-3-411-7131
http://www.acceptediting.tw
1F., No.208, Fuyuan Rd., Longtan Township, Taoyuan County 325, Taiwan (R.O.C.)
B1. Comment: If possible, arrange and resize the Figure. 6 (a) and the (b) as the same size.
Response:
Figure 6 (a) and (b) has been resized for well reading. Thanks for reviewer reminding
Revise:
Please see the revised Figure 6.
B2. Comment: The final results (Table 6 ~ 8) can be depicted as figures for the readers understanding.
Response:
Because the overall values for two pumping experiments need Tables 6 – 8 to list, the authors would like to keep these tables in manuscript. The new Figure 18 is added following reviewer’s suggestion, in order to easily realize the tendency of pumping elements in anti-phase vibration, in-phase vibration, and single plate. Since the value in Table 6 has large difference from that in Tables 7 and 8, we only compared with the data from the last two Tables as shown in Figure 18.
Revise:
Please see the added Figure 18.
Please see the last paragraph in “Section 3. Experimental and Numerical Results”.
The results of the flow rate and the flow velocity of the pumping element for anti-phase and in-phase vibration are listed in Table 6(a)-(b) and Table 7(a)-(b). …... As shown in Figure 18, the pumping efficiency is presented on the results of increment of velocity from the value listed in Tables 7 and 8. It is obviously shown that the anti-phase vibration of the pumping element with dual bimorph can provide the better feature than those with single bimorph, because of the compression effect by two bimorphs which deform in the opposite directions.
B3. Comment: As the main subject of this manuscript, comparisons of single and two layers of bimorph should be done intensively.
Response:
The average flow velocity and the velocity increments of single and dual-bimorphs are shown in Table 7, 8 and summed up in the last paragraph on Section 3. The average flow velocity and the velocity increments are larger for the dual-bimorph device with anti-phase motion. This is what we emphasize mostly because the efficiency is important for the pump development. In order to realize easily for reader, the authors added the Figure 18 according to reviewer’s suggestion.
Moreover, the previous study on the experimental and theoretical results for single bimorph can be found in the published paper [25]. Compare the results of these two studies, the revision is added the illustration in the last paragraph on Section 3. As the “Table Appendix” below shows (data from this study and the previous study), the resonant frequencies obtained from AF-ESPI and FEM for single and dual-bimorph are close. For the in-air case, the single-bimorph has the slightly higher frequencies in most modes. To avoid on the article too long, the following table is abandoned to put in article but only descript in context.
Revise:
Please see the added Figure 18.
Please see the last paragraph in “Section 3. Experimental and Numerical Results”.
The results of the flow rate and the flow velocity of the pumping element for anti-phase and in-phase vibration are listed in Table 6(a)-(b) and Table 7(a)-(b)……. More experimental and theoretical results about single bimorph can be found in the published paper written by our past study [25]. The optical experiment has much more difficulties for the dual-bimorph, since one of the bimorph is fixed in the lower position, and is obstructed by another bimorph. Compare the results of these two studies, it is indicated that the mode shapes of single-bimorph and dual-bimorph are similar, and there is slight difference of the resonant frequencies between the single and dual-bimorph. The resonant frequencies decreases both in single- and dual-bimorph piezoelectric pumping element when the similar modes were excited from air changed to water or glycerine. As shown in Figure 18, the pumping efficiency is presented on the results of increment of velocity from the value listed in Tables 7 and 8. It is obviously shown that the anti-phase vibration of the pumping element with dual bimorph can provide the better feature than those with single bimorph, because of the compression effect by two bimorphs which deform in the opposite directions.
Table Appendix. The resonant frequencies obtained from AF-ESPI and FEM for single (data the previous study [25]) and dual bimorph (data from this study and the previous study).
Mode | Dual-bimorph FEM (Hz) | Single-bimorph FEM (Hz | Dual-bimorph AF-ESPI (HZ) | Single-bimorph AF-ESPI (HZ) | ||
1 | 79 | Anti-phase | 83 | 84 | Anti-phase | 82 |
79 | In-phase | 87 | In-phase | |||
2 | 491 | Anti-phase | 512 | 510 | Anti-phase | 545 |
492 | In-phase | 519 | In-phase | |||
3 | 1363 | Anti-phase | 1417 | Anti-phase | ||
1366 | In-phase | In-phase | ||||
4 | 1636 | Anti-phase | 1667 | 1660 | Anti-phase | 1760 |
1638 | In-phase | 1770 | In-phase | |||
5 | 2294 | Anti-phase | 2346 | 2410 | Anti-phase | 2485 |
2296 | In-phase | 2430 | In-phase | |||
6 | 2780 | Anti-phase | 2899 | 2865 | Anti-phase | 3020 |
2783 | In-phase | 2855 | In-phase | |||
7 | 3443 | Anti-phase | 3539 | 3620 | Anti-phase | 3730 |
3446 | In-phase | 3655 | In-phase | |||
8 | 4589 | Anti-phase | 4783 | 4555 | Anti-phase | 4820 |
4593 | In-phase | 4560 | In-phase | |||
9 | 4957 | Anti-phase | 5101 | 5125 | Anti-phase | 5320 |
4960 | In-phase | 5150 | In-phase |
Author Response File: Author Response.pdf
Reviewer 3 Report
The paper is in acceptable from in terms of English language and quality of results. Overall, the research topic is within the scope of the readers of this journal and is recommended to be published.
Author Response
Response to the review Comments on the manuscript
“Experimental and Numerical Investigation of Resonance Characteristics of Novel Pumping Element Driven by Two Piezoelectric Bimorphs”
(Manuscript No.: applsci-471529)
Yu-Chih Lin, Yu-Hsi Huang*, and Kwen-Wei Chu
The revised version of the manuscript has been made according to the comments of reviewerw #1, 2, 3 and 4.We are very grateful to their valuable comments which improve the quality of the paper. We mark up the corrections and changes in the revised manuscript with a yellow highlight to locate the modifications. The main revision of the manuscript and responses to the review comment are summarized as follows.
Reviewer’s comments for the revised manuscript
C. Responses to the review comments for reviewer #3
English language and style
( ) Extensive editing of English language and style required
(x) Moderate English changes required
( ) English language and style are fine/minor spell check required
( ) I don't feel qualified to judge about the English language and style
Yes Can be improved Must be improved Not applicable
Does the introduction provide sufficient background and include all relevant references?
( ) (x) ( ) ( )
Is the research design appropriate?
( ) (x) ( ) ( )
Are the methods adequately described?
( ) (x) ( ) ( )
Are the results clearly presented?
( ) (x) ( ) ( )
Are the conclusions supported by the results?
( ) (x) ( ) ( )
Comments and Suggestions for Authors
The paper is in acceptable from in terms of English language and quality of results. Overall, the research topic is within the scope of the readers of this journal and is recommended to be published.
Response:
Thanks for reviewer’s positive opinion and encouragement.
Author Response File: Author Response.pdf
Reviewer 4 Report
The paper presents an experimental characterization of dual-bimorph piezoelectric pump device by considering fluid-structure coupling. The numerical simulations are carried out to verify the experiments and show reasonable verification. For obtaining the resonant frequencies of the device, several measurement devices are employed, including Amplitude-fluctuation electronic speckle pattern interferometer, laser Doppler vibrometer, and impedance analyzer. The resonant frequency results confirm the close correspondence between different measurements, which is expected.
Overall, the study is very interesting since it helps the readers of the field to get a good sense of different characterization techniques; therefore, it makes a good contribution to the Applied Sciences journal. I have several minor comments that should be addressed in the paper before publication:
· Please merge Fig. 1 and 2 together and increase the figure quality; there are so much drawing details in Fig.2(a)-(b) that are unnecessary to present in the paper. You could just use Fig.2(c)-(d) and combine it with Fig.1 to present the whole schematics.
· Fig. 4 is unnecessarily big. Please arrange the figure again, and put Fig. 3 as an inset inside the Fig. 4; This way, the full experimental picture is visible in one figure.
· Please put an electrical connection configuration graph in a figure before Fig. 7, to differentiate the in-phase and anti-phase motion of the piezo-beams. It would help the reader to understand which configuration you used for in-phase/anti-phase excitation.
· For LDV measurements, change all the displacement plots to have logarithmic Y-axis.
· In general, please reorganize Fig. 7-9; the bold fonts are so big and confusing. In addition, it would be nice to show the comparison of mode shapes between different mediums (air, water, glycerol) by putting the ESPI graphs in one row for each mode.
Author Response
Response to the review Comments on the manuscript
“Experimental and Numerical Investigation of Resonance Characteristics of Novel Pumping Element Driven by Two Piezoelectric Bimorphs”
(Manuscript No.: applsci-471529)
Yu-Chih Lin, Yu-Hsi Huang*, and Kwen-Wei Chu
The revised version of the manuscript has been made according to the comments of reviewerw #1, 2, 3 and 4.We are very grateful to their valuable comments which improve the quality of the paper. We mark up the corrections and changes in the revised manuscript with a yellow highlight to locate the modifications. The main revision of the manuscript and responses to the review comment are summarized as follows.
Reviewer’s comments for the revised manuscript
D. Responses to the review comments for reviewer #4
English language and style
( ) Extensive editing of English language and style required
( ) Moderate English changes required
(x) English language and style are fine/minor spell check required
( ) I don't feel qualified to judge about the English language and style
Yes | Can be improved | Must be improved | Not applicable | |
Does the introduction provide sufficient background and include all relevant references? | (x) | ( ) | ( ) | ( ) |
Is the research design appropriate? | (x) | ( ) | ( ) | ( ) |
Are the methods adequately described? | (x) | ( ) | ( ) | ( ) |
Are the results clearly presented? | ( ) | (x) | ( ) | ( ) |
Are the conclusions supported by the results? | (x) | ( ) | ( ) | ( ) |
Comments and Suggestions for Authors
The paper presents an experimental characterization of dual-bimorph piezoelectric pump device by considering fluid-structure coupling. The numerical simulations are carried out to verify the experiments and show reasonable verification. For obtaining the resonant frequencies of the device, several measurement devices are employed, including Amplitude-fluctuation electronic speckle pattern interferometer, laser Doppler vibrometer, and impedance analyzer. The resonant frequency results confirm the close correspondence between different measurements, which is expected.
Overall, the study is very interesting since it helps the readers of the field to get a good sense of different characterization techniques; therefore, it makes a good contribution to the Applied Sciences journal.
Response:
Thanks for reviewer’s opinion and encouragement.
D1. Comment: Please merge Fig. 1 and 2 together and increase the figure quality; there are so much drawing details in Fig.2(a)-(b) that are unnecessary to present in the paper. You could just use Fig.2(c)-(d) and combine it with Fig.1 to present the whole schematics.
Response:
The complete size information as shown in Figure 2 might be not good to delete. We had known that the fluid boundary (range and depth) is also the important issue to influence on the solid-liquid coupled vibration from our advance research. Besides, the reviewer # 1 would like to know the unit of pumping element to revise on Figure 2.
D2. Comment: Fig. 4 is unnecessarily big. Please arrange the figure again, and put Fig. 3 as an inset inside the Fig. 4; This way, the full experimental picture is visible in one figure.
Response:
The authors had ever trial following reviewer’s suggestion put the element as shown in Figure 3 into the schematics as shown in Figure 4. The pumping elements became poor resolution. Moreover, Figure 3 emphasized on the combination with piezoelectric bimorph and pumping element, and Figure 4 focused on the optical arrangements for the measured system of up- and down- piezoelectric specimens. The authors are still following the reviewer’s suggestion to shrink almost 22% area in revised Figure 3.
Revise:
Please see the revised Figure 3.
D3. Comment: Please put an electrical connection configuration graph in a figure before Fig. 7, to differentiate the in-phase and anti-phase motion of the piezo-beams. It would help the reader to understand which configuration you used for in-phase/anti-phase excitation.
Response:
The electrical connections for anti-phase and in-phase motions are shown as the added Figure 7. Thanks for reviewer’s opinion improving the reader’s understanding.
Revise:
Please see the added Figure 7 and the second paragraph on “Sec. 2.6 The Flow Rate and Flow Velocity Measurement”.
Figure 7 shows the electrical connection of dual piezoelectric bimorphs to drive in anti-phase and in-phase motions. The various electrical fields applied on the upper- and lower-layer piezoelectric ceramics with different polarization to produce on larger bending deformation, since the shrinkage and extension cause respectively by the same and the opposite directions between electrical field and polarization. The deformation mechanism on piezoelectric bimorph was discussed in detail by Huang and Ma [24].
D4. Comment: For LDV measurements, change all the displacement plots to have logarithmic Y-axis.
Response:
Although the logarithmic response curve is easier to recognize the smaller peaks in higher resonant frequencies, the authors would like to keep showing in linear scale because the pumping effect in this research is utilized on the volumetric change. The water-coupled modes has larger vibrating displacement before 1 kHz as shown in Figure 12, that is corresponding to the pumping efficiency better performed on those modes as shown in the revised Figure 18.
D5. Comment: In general, please reorganize Fig. 7-9; the bold fonts are so big and confusing. In addition, it would be nice to show the comparison of mode shapes between different mediums (air, water, glycerol) by putting the ESPI graphs in one row for each mode.
Response:
The setup in bold font has been canceled out as shown in revised Figures 8-10.
Revise:
Please see the revised Figures 8-10.
Author Response File: Author Response.pdf
