Programmable droplet sliding on slippery surface with tunability in both surface microstructure and lubricant

Smart slippery surfaces with intelligent liquid droplet manipulation performance have aroused much attention. The lubricant and surface microstructure are two key factors that govern the droplet’s sliding performance. However, for almost all existing surfaces, only one factor can be regulated, which significantly limits their wetting performances and applications. Herein, by integrating the temperature-responsive lubricant and shape memory surface microstructure, we report a novel slippery surface. On this surface, the solid/liquid phase transition of the lubricant provides the surface with the ON/OFF control for droplet’s movement between the sliding state and pinning state, and the tunable surface microstructure based on material’s shape memory effect offers the programmable sliding directions. Due to the combined effect, diverse liquid transportation programs with random ON/OFF manner and arbitrary direction were further demonstrated on this surface. This work advances a new slippery surface with controllable lubricant and surface microstructure, which not only provides insights into the design for smart slippery surfaces but also provides a promising material for application in smart control of droplet motion. A novel shape memory slippery surface is prepared, on which both the lubricant and surface microstructure can be reversibly controlled.