Surfaces with switchable adhesion have been vigorously investigated over the past decades by mimicking the unique adhesive mechanisms of living systems. However, designing a universal intelligent adhesive surface for both solid and liquid remains a challenge. Herein, drawing inspiration from the controllable capillary forces generated by muscle movements and oil-secretion on the foot pads of the beetle ( Hemisphaerota cyanea ), we report a novel oil-loaded shape memory polymer (SMP) micropillars with such smart controllability. Based on the shape memory effect (SME) of the SMP, the pillars can be reversibly switched between the tilted state and the upright state, which simultaneously changes the distribution of the trapped oil, and thus generates different capillary forces. This variation results in reversible adhesion behaviors of the surface to diverse solids including flat glass, CD disk, polytetrafluoroethylene (PTFE), rough glass, sandpaper, nylon net, and liquid droplets like acid, basic, salt-containing water droplets, and some organic liquids such as glycol, glycerol, and formamide. Given its smart adhesion, the surface was further applied in in-situ gripping/release of solid objects and directed liquid shedding. This work provides a new design strategy for smart adhesive materials, which may contribute to the development of smart grippers, microfluidics, etc.
Azobenzene-mesogen photo-actuator is frequently utilized in diverse bionic motions due to their unparalleled advantages of wireless and reversible actuation. The realm of jumping behavior remains unexplored for azobenzene-based actuators. Inspired by the Click-beetles, here a Janus light-driven jumping robot is achieved through the integration effect of an azobenzene molecule (with a short thermal relaxation time) and a splay alignment. The prepared Azobenzene liquid crystal films exhibit remarkable light-driven continuous jumping capabilities, with jumping heights of 35 body lengths (BL) and takeoff speeds of 0.67 m s −1 (670 BL s −1 ), these data currently surpass the performance of small-mass jumping robots. This research will be helpful for the design of novel actuators and broaden of the application scenarios of azobenzene actuators.
危险品化学品经营许可证（带存储）