Photoresponsive Soft-Robotic Platform: Biomimetic Fabrication and Remote Actuation

Biomimetic microsystems, which can be driven by various stimuli, are an emerging field in micro/nano-technology and nano-medicine. In this study, a soft and fast-response robotic platform, constituted by PDMS/graphene-nanoplatelets composited layer (PDMS/GNPs) and pristine PDMS layer, is presented. Due to the differences in coefficient of thermal expansion and Young's modulus of the two layers, the bilayer platform can be driven to bend to the PDMS/GNPs side by light irradiation. The robotic platform (1 mm in width and 7 mm in length) can be deflected about 1500 mu m by near infrared irradiation (nIR)(808 nm in wavelength) within 3.4 s, and excellent reversibility and repeatability in actuation are also revealed by sweeping and multicycle light irradiation. The experiments also show that, the presented bilayer platform in various shapes, that is, fish-like shapes, can float and swim to perspective location in fluid (i.e., water), whose moving directions and velocities can be remotely adjusted by light, indicating an excellent light-actuation ability and well controllability. The results may be not only hopeful in developing light-driven drug-delivery platform, but also the bio-robotic microgrippers applying in vivo and in vitro.