Multiphase\nJanus Azobenzene Inverse Opal Membrane\ntoward On-Demand Photocontrolled Motion

Azobenzene\nactuators have generated extensive research investment\nin the field of soft robots, artificial muscles, etc., based on the\ntypical photoresponsive <i>trans</i>-<i>cis</i> isomerization. However, it remains challenging to achieve multiphase\nactuation at the gas–liquid interface and liquid phase. To\nsolve these problems, this paper demonstrated a simple fabrication\nmethod of a Janus azobenzene inverse opal membrane with one side having\na polydomain azobenzene inverse opal structure and the other side\nhaving a monodomain bulk azobenzene polymer. The introduction of an\ninverse opal structure increases the interaction area between the\nliquid and polymer network. The proposed design can freely swim in\nany direction at the air–liquid interface based on the Marangoni\neffect or move forward in the liquid phase based on bubble propulsion\nunder UV irradiation. This work is of great significance for the design\nand fabrication of multiphase photo actuators.