Chromatic surface microstructures on bionic soft robots for non-contact deformation measurement

This paper presents a bionic soft robot with chromatic surface micro-structure (CSM), as a new approach for the measurement of body deformation of the soft robots. Firstly, the CSM films are fabricated by diffraction gratings mold using material polydimethylsiloxane (PDMS). Then, the CSM films are attached to the surface of the soft actuators based on shape memory alloy (SMA) wires. By recording and matching the pattern through two cameras, the continuous deformation curvature degrees of SMA soft actuators are attained. Finally, by integrating three actuators mentioned previously, a bio-inspired prototype of three-legged soft robot is manufactured to carry out motions of both freely and grasp obstacles. By recording and matching the pattern of the robot, we demonstrated a non-contact deformation measurement for flexible devices. As a new non-contact measurement method for body deformation of soft robots, it may shed some light on the issues of the soft robots' sensing and controlling in the future.