Pinning/sliding behaviors and underlying mechanism of water droplets on ultra-slippery surfaces under temperature and force fields stimuli

In recent years, stimuli-responsive slippery liquid-infused porous surfaces (SLIPSs) have attracted widespread attention in the field of microfluidic manipulation. However, most reported responsive SLIPSs function under a single stimulus, which are challenging to satisfy the generalized application scenarios. Here, a kind of dual-responsive slippery surface (DRSS) is fabricated through femtosecond laser cross-scanning method. Relying on the synergic action of temperature and force field, the sliding/pinning behaviors of water droplets on DRSS can be dynamically controlled. The impact of diverse parameters on the critical sliding volume of droplets is systematically investigated, including lubricant infusion amount, groove depth and spacing. The dynamic mechanism of droplet sliding/pinning behaviors is revealed. This kind of DRSS could be used in the related fields such as lab-on-a-chip and microfluidic reactors.