Design and Experimental Study of Cavity Structure of Pneumatic Soft Actuator

Round 1

Reviewer 1 Report

1. The language of this paper needs to be improved.

2. The number of reference needs to be increased. In addition, please refer to the latest literature as much as possible.

3. The authors should try to establish a theoretical model of the actuator.

4. Please explain the shortcomings of this work and future work in the conclusion.

The language of this paper needs to be improved.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear Author(s),

I have thoroughly reviewed the manuscript. While it offers a certain contribution, some aspects could be improved upon before it's ready for publication.

1.       In the introduction, I suggest including several relevant studies (Chen et al., 2018; Li et al., 2019; TolleyMichael et al., 2014) to give a more comprehensive backdrop to your research.

2.       Section 2.2 would benefit from the addition of the silicone rubber manufacturer's details. Moreover, I find a discrepancy in the choice of E620 silicone as your experimental material. You mentioned that: “By comparing the parameters of different models of silicone, it can be seen that E620 translucent molded silicone has better tear strength and tensile rate, so E620 silicone is chosen as the experimental material of soft body driver in this paper.” whereas Table I indicates E626 to have the best tensile and tear strength. Could you please clarify this? Also, kindly cite the source if the parameters in Table 1 are not your measurements.

3.       The section "Numerical simulation method for soft body drive" should be labeled as 2.5 instead of 2. Furthermore, your choice of a 2nd order Yeoh model with coefficients C10 = 0. 11 and C20 = 0. 02 needs further explanation. Could you detail how you determined these parameters?

4.       Tables 2 and 3 consume substantial space yet are discussed briefly. Consider converting these tables into a figure for easy comparison between the simulations and experiments. You don’t have to show all the figures. Only include the 0, 5 and mixed angle under one or two pressure, such as p=4 and 16 kPa. The rest of the figures can be relegated to a newly created appendix section.

5.       On page 7, you mentioned that “The bending rate of the soft actuator with mixed variable angle is decreasing with increasing pressure”. It seems to be redundant as this appears to be true for all cases. If there's no unique characteristic for the mixed variable angle case, this statement might be unnecessary.

By addressing these comments, your manuscript should see a significant increase in clarity and depth, enhancing its readiness for publication.

Chen, Z., Liang, X., Wu, T., Yin, T., Xiang, Y., Qu, S., 2018. Pneumatically actuated soft robotic arm for adaptable grasping. Acta mechanica solida sinica 31, 608-622.

Li, T., Zou, Z., Mao, G., Yang, X., Liang, Y., Li, C., Qu, S., Suo, Z., Yang, W., 2019. Agile and resilient insect-scale robot. Soft robotics 6, 133-141.

TolleyMichael, T., ShepherdRobert, F., GallowayKevin, C., WoodRobert, J., WhitesidesGeorge, M., 2014. A resilient, untethered soft robot. Soft robotics.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Major Corrections 

1. At the end of the introduction, there should be a paragraph showing clearly what is going to be developed in the manuscript. Please, improve this last paragraph at the end of the introduction. 
2. The conclusions must be improved and possible future works that can be continued with this work should also be explained. 
3. The results obtained should be compared with similar works obtained by other researchers, so that the relevance of the results obtained can be discussed. 
4. What is the reason for choosing the Yeoh model with 2 coefficients to define the hyperelastic behavior of the elastomer? How were these coefficients determined? 
5. The reader would be grateful if the authors of the manuscript determined the error between the data obtained experimentally and those obtained from the proposed FEM model (figure 8) using a MAE or RMSE. 
6. the sequence of images in table 2 and table 3 should be displayed in a better way since they take up too much space and there is a large space between each of the sequences. Authors may delete some of the images or reduce the space between them. It is not correct that each of the table occupies more than one page of the manuscript. 
7. It would be interesting for the authors to detail the following sections of the FEM  model that they have proposed since it is very important to obtain good simulation  results, especially when trying to solve a mechanical problem. Please include the following points: 
   1. The boundary conditions of the proposed FEM model should be better explained.  Please specify. 
   2. Was any sensitivity analysis of the proposed FEM model performed? has been the mesh size considered by the authors in the FE models proposed? Please specify. 
   3. Has any mesh quality analysis been performed on the proposed FEM models? that  is, aspect ratio, jacobian rate, etc. These indicators are very important to determine the  quality of the mesh. Please  specify. 
   4. What type of contact algorithm was considered in this case to simulate the impact? Please specify 
   5. How was the projectile considered in this case? like a rigid body? like a deformable body? Please specify 
   6. In order to facilitate the authors to improve their manuscript, the following papers  show how their authors solved some of the key questions and points that should be  improved in this manuscript for the FEM (Mesh sensitivity analysis, mesh quality,  boundary conditions, MAE and RMSEetc). I suggest that the authors review the attached papers as they  can facilitate the improvement of their manuscript. 
      
       

• Finite element model updating combined with multi-response optimization for hyper-elastic materials characterization 
• Bulge test application in the characterization process of elastomer materials membranes 
• Residual stresses with time-independent cyclic plasticity in finite element analysis of welded joints 
• Comparative analysis of healthy and cam-type femoroacetabular impingement (FAI) human hip joints using the finite element method  
• Determination of the contact stresses in double-row tapered roller bearings using the finite element method, experimental analysis and analytical models 

Minor Corrections 

The authors must be sure that the figures, tables and references must be in accordance with the format of the journal. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

good morning. Having reviewed the new version provided by the authors,
I consider that the modifications made are appropriate to the considerations made.
From my point of view the article can be published