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

Abstract

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: ≈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.

Light-Triggered Transmittance Control in Thermoresponsive Hydrogels by Femtosecond Laser Direct Writing

“…It has been reported that the inclusion of light absorbers in the thermoresponsive hydrogel can change the wavelength where the hydrogel shows a light response. , As an example of imparting visible or near-infrared light responsiveness to poly­( N -isopropylacrylamide) (PNIPAM) hydrogels, previous studies have reported the method of including metal nanoparticles to a thermoresponsive hydrogel. − Notably, the multiphoton photoreduction allows for the patterning of microstructures composed of metal nanoparticles within a thermoresponsive hydrogel, − enabling spatially selective and high-resolution responsiveness to light stimuli in the visible and near-infrared wavelengths. The light responsiveness of hydrogels is determined by the density of metal nanoparticles generated within the hydrogel, which serves as a light absorber.…”