Self-Driving Behavior and Pinning Effect of Droplets on GrapheneCovered Functional Textured Surfaces

Biological features such as the bumps on back of desert beetles and spikes cacti enable directional transport water droplets, creating conditions for their survival in nature. Inspired by interesting natural phenomenon, a novel design nanopillared surface with gradient density structural pillar matrix covered monolayer graphene is proposed to realize ultrafast self-driving droplets. The droplet can move spontaneously at ultrahigh speed 75.7 m/s (272.52 km/h) from sparsest densest regions pillars while wettability created distribution relying wetting transparency graphene. In particular, short pillared texture triggers an opposite regularity which moves pillars, intrinsically because short-pillared leads transition hydrophobic hydrophilic since be adsorbed into texture. Furthermore, graphene-covered nanocone (GNC) tip end GNC. rule energy change during selfdriving process indicates that potential interaction between GNC undergo cooperation competition successively, resulting first speeding up then slowing down steady moving state. Continuum theory microscale used describe process, order further understand GNC-based transport. However, pinning effect induced defects usually restrain droplets functionalized surfaces. Thus, mechanism revealed based molecular dynamic simulations motion behaviors copper substrate different shaped defects. results show defected solid remarkably reduce processes. A large damping force will appear when initially approaches finally away pure substrate, whereas tiny observed across Particularly, consequent extra-damping appears nano-configuration changed after passing deformation process. These findings explore role reducing resistance self-driving, have theoretical significance graphenecovered functional surfaces