Fig. 3
Actuation mechanism of the nano channel membrane. a Schematic representation of the vapor-responsive bending principle of the actuator (when vapor approaches one side of the single-layer membrane, the molecular channel adsorbs the vapor and the surface undergoes swelling, resulting in the film bending upon exposure to the vapor source). b Single-layer membrane bending and reversing actuation synchronizes with weight change when the vapor was pumped in and out. c Single-layer membrane bending behavior with weight change when the vapor was retained in the chamber. d Schematic representation of the molecular channel expansion process. e Maximum bending angles of the single-layer PFSA actuator triggered by various solvent vapors. (2 kPa, 20 °C)
