Direct Ink Writing of a Light-Responsive Underwater Liquid Crystal Actuator with Atypical Temperature-Dependent Shape Changes

In recent years, light-responsive liquid crystal (LC) polymers have been studied as promising materials for the fabrication of untethered soft actuators. The underwater behavior of these advanced materials has, however, been rarely investigated. This paper reports on the fabrication of light-responsive amphibious LC-actuators via direct ink writing (DIW). The actuators present two underwater deformation modes triggered by different stimuli. Temperature induces contraction/expansion and light induces bending/unbending. Unexpectedly, temperature can regulate the bending directionality, giving the material additional versatility to its deformation modes. These findings serve as a toolbox for the fabrication of light-responsive actuators via DIW that operate in air and underwater.