LAUSR

Shape memory polymer (SMP) surfaces with tunable wettability have attracted extensive attention due to their widespread applications. However, there have been rare reports on in-situ tuning wettability with SMP materials. In this paper, we reported a kind of distinct superhydrophobic SMP microconed surface on silver nanowire (AgNW) film to achieve in-situ reversible transition between pinned and roll-down states. The mechanism is taking advantage of the in-situ heating functionality of silver nanowire film by voltage, which provides the transition energy for SMP to achieve the fixation and recovery of temporary shape. It is noteworthy that the reversible transition could be repeated many times (> 100 cycles) and we quantitatively investigate the shape memory ability of microcones with varied height and space under different applied voltage. These results show that the tilted microcones could recover its original upright state under a small voltage (4 ~ 11 V) in a short time, and the shortest recovery time is about 0.5 min under an applied voltage of ~ 10 V. Finally, we utilize SMP microcone arrays with tunable wettability to realize lossless droplet transportation, and the tilted microconed surface also achieve liquid unidirectional transport due to its anisotropic water adhesion force. The robust microconed SMP surface with reversible morphology transitions will have far-ranging applications including droplet manipulation, reprogrammable fog harvesting, and so on.