Magneto-Photochemically Responsive Liquid Crystal Elastomer for Underwater Actuation.

The quest for small-scale, remotely controlled soft robots has led to the exploration of magnetic and optical fields for inducing shape morphing in soft materials. Magnetic stimulus excels when navigation in confined or optically opaque environments is required. Optical stimulus, in turn, boasts superior spatial precision and individual control over multiple objects. Herein, we bring these two methodologies together and present a monolithic liquid crystal elastomer (LCE) system that synergistically combines magnetic and photochemical actuation schemes. The resultant composite material showcases versatile possibilities for underwater actuation, and we demonstrate robotic functionalities where the optical and magnetic response can be leveraged in different tasks (object gripping and object translocation, respectively) or where light can be used as a control signal to tune the magnetically induced actuation. Combining these two remote actuation methods offers powerful, dual-mode control in wireless, small-scale robotics, especially in submersed environments due to their isothermal nature.