PONE-D-20-05874

Negshell casting: 3D-printed structured and sacrificial cores for soft robot fabrication

PLOS ONE

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Reviewer #2: Yes

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Reviewer #1: The authors presented a novel fabrication method for soft robots. In this paper, the negshell casting was used in the bellow-jointed finger. The experimental data fit well with the original design idea. However, the reviewer still have some comments:

1. The fragment of the negshell may do harm to the soft material, and reduce the life of the robot.

2. Also, the fragment of the negshell may block the inner channel of the robot.

3. In my opinoin, the authors should consider the circle life of the actuator due to the questions I mentioned above.

Reviewer #2: The manuscript, "Negshell casting: 3D-printed structured and sacrificial cores for soft robot fabrication" by Preechayasomboon and Romobokas, presents an interesting idea that can be employed in fabricating 3D-printed structures, especially for soft robotics. When fabricating a hollow 3D printed structure using stereolithography (SLA) based methods (and, in fact, with fused deposition model (FDM) based methods as well), users face problems of dealing with unwanted auxiliary structures. When a 'hollow' space is programmed, such space is usually filled with artifacts with some geometric features that the printing algorithm determines. Such filled artifacts are often nuisance. The authors of this manuscript made a contrarian perspective to design 'sacrificial artifact' to fill the internal volume when 3D-printing such hollow structure, and named this fabrication method as "negshell casting", as an acronym for negatice-space eggshell casting.

I rate this idea to be extremely practical and useful. Although this is not a profound science, such simple idea can really make contribution to wide fields of science and engineering that utilizes 3D printing as a tool. The authors included details in design and fabrication, and included an interesting application example of a pneumatic gripper that can perform pick and place. The detailed writing style of the manuscript is consistent with the purpose of PLOS ONE as an open-source of ideas. I would like to recommend a publication of this paper with the current form.

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Negshell casting: 3D-printed structured and sacrificial cores for soft robot fabrication

PONE-D-20-05874R1

Dear Dr. Preechayasomboon,

We are pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it complies with all outstanding technical requirements.

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With kind regards,

Ning Cai, Ph.D.

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments: