Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The paper presents a piezoelectric energy harvesting and management circuit.The full-bridge rectifier is well know. Also the management circuit comes from former work. 

 

So, which is the novelty of the work?

 

Comparison with the state-of-the-art and respectively the comparison table should be enlarged.

 

In Fig. 10, on the right side, a reference ground is missing.

 

The 2 only measurement plots provided are not clear.

 

Once the author claims the presence of a test chip, no sense in having many more simulation plots than measurement results.

 

Please increase the number of measurements, considering possible also PVT variations.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

I think some changes are needed before carefully consider the manuscript. No circuital novelties are there (rectifier, comparator and LDO are known); the comparison table (table 1) lists other 3 works, all of them present excitation type constant and maximum power point circuit. Therefore the performance comparison is meaningless in my opinion.

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors What are the geometrical and material parameters of the cantilever to be applicable in combination with the proposed circuit? What voltage and frequency must be generated to be able to convert it with a minimum loss of energy?   What is your motivation for avoiding voltage doubler or quadrupler if you need higher power for multiple sensor nodes?   You must compare the proposed solution for the circuit with the existing commercial ones. Reference https://doi.org/10.3390/app14114792 can be helpful, as it already summarizes some of the available solutions.   There are few commercially available circuits specially designed for low-power vibration energy harvesters - LTC3588-1, AD5091 etc. What do you improve compared to the existing commercial solutions? How does your design compete? A table of comparison is needed for all key specification parameters.

All explanations are too general. Specify what sensors you want to supply concretely and what piezoconverter you use.

Can you analyze how much miniaturization is hindered due to the magnet
insertion? What is the overall size of this PEH system? Is it integrated on the same chip?   It is unclear what are the benefits of using this approach with voltage divider and two comparators.   It is unclear what is the novelty of the proposed configuration that is the first time implemented.   The analysis is mainly based on simulations, and the experimental measurement work is insufficient. The measurements that were conducted were not compared with the simulations to explore the differences and suggest optimizations.   Justification of the selected package, considerations at package selection and reliability is not mentioned, which is compulsory in the development of device at a system level.

 

 

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors address my request

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The paper has been improved, however some changes are still mandatory in my opinion, because the novelty is marginal and therefore the practical implementation and fabrication of the circuit (and the comparison to the state of the art) must be very clear to highlight the advantages of the proposed circuit.

The comparison table should compare the circuits fairly. It is clear, in my opinion, that the results of the proposed circuit are from simulations and not from measurements. Please, move the table to the measurement section and provide measurement results instead of simulation ones. 

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The authors' response is detailed, but some of them don't adequately address the question raised, and their justification is not convincing. The manuscript itself is not very much modified since the initial version, or at least a small number of comments are marked as newly added. The main concern of mine (as I can see, the situation is the same with the other reviewers) is highlighting the novelty. This comment is not at all addressed, and not highlighted in the text. The justification of point-by-point response is not sufficient as a scientific merit to explain a novelty. Regarding all other questions like: "There are few commercially available circuits specially designed for low-power vibration energy harvesters - LTC3588-1, AD5091 etc. What do you improve compared to the existing commercial solutions? How does your design compete? A table of comparison is needed for all key specification parameters. All explanations are too general. Specify what sensors you want to supply concretely and what piezoconverter you use." the authors don't present clear, relevant and concrete answers. Moreover, there is an engineering conceptual error - "key specification of the sensor is currently not available to us" the authors responded - it is not possible to engineer workable device if the sensor to be powered has unknown parameters, because the problems with the load effect and impedance matching appear. "However, the focus of this paper is to show our interface circuit design and validation." - it is not possible to validate an interface circuit without the object of interfacing. Therefore, I cannot recommend this manuscript for publication.

Author Response

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Author Response File: Author Response.pdf

Round 3

Reviewer 2 Report

Comments and Suggestions for Authors

the paper has been modified accordingly to the suggestions