Biomorphic Actuation Driven Via On-Chip Buckling of Photoresponsive Hydrogel Films

Remotely controllable photoresponsive hydrogel actuators are promising for applications in multiple fields. However, simple deformation mechanisms, which rely on the general swelling/deswelling, limit their performance and application. Herein, we report a displacement amplification mechanism based on the buckling deformation of photoresponsive hydrogel film. The on-chip buckled architecture of the hydrogel enables actuation between a flat 2D shape and tubular 3D buckled shape with remarkable performances, including high deformation ratio (height ratio: approximate to 360%), tunable cycle motion frequency (0.1-1 Hz) and high cyclic stability. Moreover, localized buckling deformation, such as tube opening and closing, can be controlled in response to photostimulation. Inspired by these biomorphic shapes and motions, an intestine-mimetic device and demonstrate segmentation with substance crushing and peristalsis motion with substance propelling were further fabricated. This study will provide a useful design principle for hydrogel actuators and shed light on diverse applications in soft robotics, dynamic microfluidics and organs-on-chips.