Direct 3D printing of silicone elastomer soft robots and their performance comparison with molded counterparts

Additive manufacturing has a wide range of applications and addresses many challenges inherited from conventional molding techniques such as human error, multistep fabrication, and manual handling. However, 3D printing soft functional robots with two-part platinum cure silicones requires development to match the material performance of the molded counterparts. In this paper, we present a custom 3D printer and an extrusion mechanism capable of 3D printing soft functional robots. Moreover, we compare the performance differences between our 3D printed soft robots and molded counterparts via lamination casting and lost wax casting. We validate our results by conducting multiple experiments such as blocked force, bend angle, failure pressure, and dimensional quality analyses. We demonstrate that our method enables 3D printing of soft robots that can perform better, or match the performance of molded counterparts while being more reliable and robust with the usage of the same materials.