A programmable 3D printing method for magnetically driven micro soft robots based on surface tension

Abstract

The micro soft robot which mimics the movement of microorganisms is one of the important research directions in the field of robotics. This study proposes a programmable 3D printing method for magnetically driven micro soft robots based on surface tension. High-performance surfactant was used to reduce the surface free energy of the printing substrate, so that the liquid printing material can maintain a stable shape under the effect of surface tension. Pre-printed auxiliary lines with ultraviolet curing adhesive made the subsequently printed silicone maintain its shape defined by the auxiliary lines in the plane, and the thickness of its shape was adjusted by controlling the total amount of silicone. Silicone mixed with and without neodymium–iron–boron powder was printed into different areas successively, which eventually combined into a magnetically driven micro soft robot with a specific two-dimensional structure. Magnetically driven motion experiments confirmed that micro soft robots with different driving modes can be manufactured by this 3D printing method, and the influences of printing parameters as well as magnetically driven parameters on the motion performance of the microrobots are studied.