Wireless flexible strain sensing skin based on structural color visual sensing

Abstract

Flexible strain sensors, with their excellent stretchability, are widely used in wearable devices and robotics. However, most existing flexible strain sensors are wired electronic sensors, which suffer from limited flexibility and environmental adaptability. To address this issue, a wireless visual sensing scheme based on structural color is proposed. This structural color sensing skin exhibits changes in grating microstructure periodicity as strain decreases from 120% to 0%, with the reflected light hue shifting from 124 hue (redshift) to 10 hue. This design enables wireless sensing by intuitively reflecting stress and strain changes through visible color variations. The structural color sensing skin is integrated into the surface of a pneumatic rehabilitation glove. As the robotic hand bends, the reflected light hue shifts from 120 hue (blueshift) to 20 hue. Through experiments, the capability of the structural color sensing skin to detect mechanical force and angular variations is demonstrated, showcasing its great potential in the field of flexible robotics.