Reversible Snapping of Constrained Anisotropic Hydrogels Upon Light Stimulations

• DOI: 10.1002/advs.202402824
• Publication Date: 2024-05-05T09:58:51Z
• Authors: Chen Fei Dai; Qing Li Zhu; Olena Khoruzhenko; Michael Thelen; Huiying Bai; Josef Breu; Miao Du; Qiang Zheng; Zi Liang Wu
• Keywords: Necking

Abstract Creatures, such as Venus flytrap and hummingbirds, capable of rapid predation through snap‐through transition, provide paradigms for the design soft actuators robots with fast actions. However, these artificial “snappers” usually need contact stimulations to trigger flipping. Reported here is a constrained anisotropic poly( N ‐isopropylacrylamide) hydrogel showing snapping upon light stimulation. This prepared by flow‐induced orientation nanosheets (NSs) within rectangular tube. The precursor containing gold nanoparticles immediately exposed UV photopolymerization fix ordered structure NSs. Two ends slender gel are clamped form buckle bistability nature, which snaps other side laser irradiation. Systematic experiments conducted investigate influences power intensity irradiation angle laser, well thickness height gel, on behaviors. further used kick plastic bead control switch state. Furthermore, synergetic or oscillated two buckles opposite directions realized inclined horizontal lasers, respectively. Such light‐steered hydrogels should merit designing robots, energy harvests, etc.