Investigation of Achieving Ultrasonic Haptic Feedback Using Piezoelectric Micromachined Ultrasonic Transducer

Round 1

Reviewer 1 Report

The paper entitled ''Investigation of Achieving Ultrasonic Haptic Feedback using Piezoelectric Micromachined Ultrasonic Transducer" is built on a solid foundation with real resources to be transformed from a conference version to a journal version. In this regard I can make the following recommendations:

1. The introduction should refer to the full range of applications such as: levitation, object handling and of course haptic interface applications.

2. The simulations in Matlab and Comsol are recommended to be described in sufficient detail to be able to be reproduced by the readers of the journal.

3. Any figure resulting from a simulation is recommended to be accompanied by an explanation of the basic elements, concepts, and constraints used.

4. It is recommended to improve the figures 6b (contrasting and much smaller letters) and figure 8 (much sharper) if possible.

5. Inattentive writing should be reviewed (as is in row 29).

5. The graphs must have units of measurement, figure 9 even if it is a simulations that I have no doubt will be confirmed experimentally.

6. The literature in this relatively recent field is very rich and in a journal version with the elements to be added I am sure it will be upgraded.

The paper is of great interest and I think it is in your best interest to publish at a level equivalent to the effort made to achieve the pMUT array. A major revision is the best solution to achieve this goal.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

- The description of the used methodology is not appropriate. Please separate the methodology into two subsections: 2.1 Design and simulation of the 40kHz PZT pMUT and 2.2 Fabrication and analysis of the PZT pMUT.

- The  methodology used to simulate structure of the pMUT needs be better detailed.

- The methodology used to fabricate the pMUT is described poorly. For example, what are the characteristics of the SOI wafer used as substrate?What are the sputtering deposition conditions of the PZT layer? what are the ICP conditions of PZT layer? How many samples were produced and characterized?

- The discussion of results should be improved. The results are shown but they were not discussed in depth. It is necessary to compare the obtained results with those presented in literature in order to make clear the contribution of the research to advances in the area of piezoelectric micromachined ultrasonic transducer.

Minor comments:

The authors could consider to add more references in order to better discuss their results and better describe the background of the field in the introduction section. Only seven references were cited. Most them are  articles published in conference proceedings. Piezoelectric micromachined ultrasonic transducer is a hot research topic. There are several recent journal articles about these devices.

The  data from reference 6 is not correct. Please delete "Author 1, A.B. (Uni- 166versity, City, State, Country); Author 2, C. (Institute, City, State, Country). Personal communication, 2012."

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

The authors present the use of the piezoelectric micromachined ultrasonic transducer for haptic feedback. After reading the manuscript, I feel the work is still not mature with many aspects unexplained. Therefore, I cannot recommend the work given the current status. The suggestions for improvements are detailed below:

1. The authors present the fabrication of the pMUT unit. However, how the pMUT arrays work together to generate the haptic feedback is not properly explained. The authors only present their results in Figures 8 and 9 without proper explanation. The simulated metrics/results are not clear from the figures with no units labelled. These figures are hardly understandable.

2. For human skin, there is a maximum frequency that the mechanoreceptors can respond to. How the proposed strategy addresses this problem?

3, It is not clear what the highlights of this work are. What is the novelty of the proposed sensing mechanism when compared to the state of the art?

4, The paper is not well-written with many grammatic errors. Just to give an example, the first sentence in the abstract:

“Ultrasound haptics is a contactless tactile feedback method that create tactile sensation by focusing high-intensity ultrasound on human skin, recently, it has been applied in commercial product.”

It should be

“Ultrasound haptics is a contactless tactile feedback method that creates the tactile sensation by focusing high-intensity ultrasound on human skin, and recently, it has been commercialized.”

I suggest the authors do thorough proofreading of their paper.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors have developed an improved version compared to the first version based on the indications. Unfortunately, the conference style remains and there are still some issues related to a careless drafting, Figure 3. The topic approached is extremely important and based on the materials available there were resources for a higher article. I believe that these small shortcomings will be upgraded in the pre-publication phases and in this sense, I recommend acceptance for publication. 

Author Response

Thanks for the comments, the Figure 3. was changed in the manuscript with yellow label.

Reviewer 3 Report

Please also add the unit for pressure (Pa) in Figure 12.

Author Response

Thanks for the comments, the Figure12. is changed in the manuscript with yellow label.