Construction of biocompatible bilayered light‐driven actuator composed of rGO/PNIPAM and PEGDA hydrogel

To construct an actuator with biocompatibility and potential use in biomedicine field, a light‐driven actuator composed of reduced graphene oxide (rGO)/poly (N‐isopropyl acrylamide) (PNIPAM) and poly (ethylene glycol) diacrylate (PEGDA) hydrogel is constructed. First, rGO/PNIPAM hydrogel is prepared by free radical polymerization and l‐ascorbic acid reduction, of which the surface temperature increases quickly under near‐infrared (NIR) laser indicating the efficient photothermal conversion of rGO. The results of cytotoxicity tests demonstrate that rGO/PNIPAM is biocompatible and has no obvious toxicity to myoblast line C2C12 cells. Second, bilayer hydrogel composed of rGO/PNIPAM and PEGDA is prepared using a similar method layer‐by‐layer. The bilayer strip bends towards rGO/PNIPAM under NIR laser. The bending is improved after reduction. The laser power density has a strong impact on the bending rate and degree. The reversible bending deformation indicates the structural stability. All the above results approve that the bilayer actuator has great potential to be applied in biomedicine fields such as organ‐on‐chip, drug‐carrier, or surgical aid.