A light-driven swimming micro-fish based on photo-responsive hydrogel

Abstract

Flexible actuators have been an important research direction in the application of bionic robots. In this paper, we prepared a composite hydrogel that can respond by light stimulation by encapsulating a photothermal conversion nanoparticle (GO) in a temperature-sensitive hydrogel (PNIP AM). Using this hydrogel as a flexible driving unit in the fabrication of micro-fish, the oscillation of the fish tail can be controllably regulated by light irradiation to provide forward momentum for the fish to swim. Under the stimulation of NIR light, the response time of the fish tail swinging to the maximum deformation and returning to the original state can be within one second. The rapid oscillation of the fish tail can be controlled by NIR light to provide forward momentum. The photo-responsive composite hydrogel is fabricated by a light-curing platform based on digital micro mirror devices, which can produce complex photo-responsive microstructures. The proposed scheme is feasible for miniaturized fabrication and application of flexible devices.