Fig. 1. Fabrication of the sheet-shaped magnetic soft millirobot and its main deformation and locomotion modes in different fluid-filled confined environments.
(A) The soft robot fabrication process. (i) The robot is cut from a magnetic composite elastomer film using laser cutting. (ii) The robot is wrapped to a nonmagnetic cylindrical rod with the help of water-soluble glue. (iii) The robot is put in a uniform 1.8-T magnetic field for magnetization. (iv) The dimensions and magnetization profile of the robot. (B) Different body deformations are optimal in different confined spaces. (i) In a big gap (δ = 1.1), the robot can curl into a C shape when is in the x-z plane. (ii), In a small gap (δ = 7.33), the robot can deform into the sinusoidal shape when is in the x-z plane. (iii) In a cylindrical tube (γ = 3.44), the robot can deform into a helical shape when is in the y-z plane. The finite element–based simulations can predict the robot body deformation modes in given boundary conditions. The red arrows indicate the direction of at that time instant. The colormap indicates the equivalent von Mises strain. The experimental environments are filled with a viscous fluid (η = 720 cSt). Scale bars, 1 mm. (C) Conceptual schematic depicting the adaptive multimodal locomotion of the sheet-shaped robot in various confined spaces with varying cross-sectional geometries and sizes. Photo Credits: Ziyu Ren, Max Planck Institute for Intelligent Systems.