Low-Cost High-Voltage Power Supply for Hydraulically Amplified Self-Healing Electrostatic Applications
, Upul Gunawardana 1, Ranjith Liyanapathirana 1, Osura Perera 1, Daniele Esposito 2, Jessica Centracchio 3 and Gaetano Gargiulo 1,*
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis proposed work is very important but there are some points to improve it
1. References are not up to date. The most recent one is published in 2021. This area of research is rich by many literature work specially 2024, 2023, 2022. Please add most recent references.
2. Comparison with the most updated work is very improtant. Please add a table of comparison with related recent work to show the importance of your proposed work.
3. Please rewrite the abstract to make it more attractive and to show the importance of what you have proposed.
4. The conclusion needed to be adjusted as well.
Comments on the Quality of English LanguageThis proposed work is very important but there are some points to improve it
1. References are not up to date. The most recent one is published in 2021. This area of research is rich by many literature work specially 2024, 2023, 2022. Please add most recent references.
2. Comparison with the most updated work is very improtant. Please add a table of comparison with related recent work to show the importance of your proposed work.
3. Please rewrite the abstract to make it more attractive and to show the importance of what you have proposed.
4. The conclusion needed to be adjusted as well.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe article entitled "Low-Cost High Voltage Power Supply for HASEL Applications" presents a low-cost HV power supply designed for HASEL applications, generating 2-10kV DC, costing under AUD$100 dollars for each board. According to the Authors, the key innovation is controlling the charging and discharging of the actuator from the supply's Low Voltage (LV) side rather than switching on the HV side with optocouplers. However, at this moment, the paper cannot be accepted. In the following, a few comments and suggestions are provided in order to improve the manuscript.
1) Use USD as a currency since most countries correlate more easily with the presented paper.
2) When citing references, use numbers instead of authors' names: "by researchers at the University of Colorado Boulder 23 in 2018(Acome, Mitchell et al. 2018, Kellaris, Gopaluni Venkata et al. 2018)". This way of writing makes it harder to understand, and it is not the MDPI standard way of referencing.
3) "In this paper, we have developed a low-cost HVPS. All the control is managed on the low voltage (LV) side, so there is no need for HV switching." Add more references to fundament and state the innovation.
4) On page 4, avoid using "issue": "However, a major 121 issue occurs when connecting the output of a positive voltage multiplier to the output of 122 a negative voltage multiplier."
5) The writing style could be less informal by avoiding using "we" and "can't". Example: "We can’t just isolate the grounds because, with different references, we cannot guar- 132 antee that the charging and discharge voltages "
6) Describe better the ground link and how you came up with this idea.
7) The caption of Figure 6 cites Table 1, which had not been presented in the text.
8) Many captions are just too long. For instance, in Table 1, the following text should not be in its caption: "From this, we measured the maximum 174 secondary voltage. Dividing the primary voltage by the secondary voltage gives the maximum 175 step-up ratio for the transformer. The frequency of this maximum voltage was also measured. 176 Note that this frequency was the same for the maximum primary and secondary coils."
9) There are no standard deviations in the Tables. Just average values are given.
10) Provide schematics and block diagrams in a supplementary file of the following circuits: "The low-voltage side requires high-frequency switching components for the H- 181 bridge and the boost converter. Both the H-bridge and boost converter require control 182 signals to regulate their operation. This can be done with a microcontroller. The H-bridge 183 must switch at a minimum frequency of 90kHz to match the transformer's operating fre- 184 quency. The boost converter should operate at a much higher switching frequency, at least 185 500kHz, for maximum efficiency. Cost is crucial, as active components like ICs are more 186 expensive than passive components. Additionally, each IC requires supporting compo- 187 nents such as resistors, capacitors, and transistors for biasing, filtering, level-shifting, and 188 other auxiliary functions."
11) In "The DRV8841 Dual H-Bridge Driver IC has been selected to drive the H-bridge. This 190 IC integrates all eight required switches in a single package to control the positive and 191 negative transformer switching. It offers additional features that enhance switching per- 192 formance and provide circuit protection. ", provide details about these features in a supplementary file.
12) In "The LV control of the HVPS is achieved through two primary methods: H-bridge 214 PWM switching and boost converter duty cycle modulation. Both methods can be con- 215 trolled with the ESP32.", provide more details about the ESP32 use (ports and software) in a supplementary file.
13) In "An analog 231 control voltage is applied to the LM555's control pin to modulate the boost converter 232 switching's duty cycle. ", provide more information, such as schematics, in a supplementary file.
14) Figure 7 is absent.
15) In "A silicon 270 compound with a breakdown voltage of 16kV/mm was potted around the HV compo- 271 nents (Figure 10). ", is it silicon or silicone? Review the use of these words in the whole manuscript.
16) "The subtotal for the HV components, LV components, and the PCB is respectively $6.28, 288 $32.45 and $50.09. The total cost of the" should not be in a caption.
17) Use the micron symbol correctly. Example: "The transformers are configured with the average primary 307 and secondary inductance measure in Table 1, which has been rounded to 75uH and 308 1075mH, respectively." on page 11.
18) Justify the text. Example of wrong formatting: caption of Figure 11.
19) Table 3 and others do not feature standard deviations.
20) Figure 20, and others have a title and do not show data points (just lines). The artwork must be improved to be more scientific-like.
21) More references are necessary to discuss the results to compare to relevant literature.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsPut the figure and its description on the same page. The descriptions are very extensive. Concentrate them a little.
The same for tables.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors have addressed all 21 issues previously pointed out by this reviewer. The paper has been thoroughly improved and rewritten. Careful work was done regarding the tables, figures, and captions. Except for a final formatting check, the work can now be accepted.
