Patterned Slippery Surface through Dynamically Controlling Surface Structures for Droplet Microarray

Patterned slippery surfaces based on the technique of slippery liquid-infused porous surface (SLIPS) have broad technological applications in biofouling, liquid handling, biomolecule collection, and droplet microarrays. However, methods to generate patterned SLIPS with flexibility and practical potential remain a technical roadblock. Here, we report an approach for generating patterned SLIPS, and by utilizing which, as a proof-of-technique application, the droplet microarrays have been presented. Our approach is based on a photocross-linkable polyelectrolyte poly(ethyleneimine)/azide-poly(acrylic acid) (PEI/PAA-N-3) film, whose surface structures can be dynamically controlled. We have prepared the surface-patterned PEI/PAA-N-3 film containing microstructured and flat regions. We then demonstrate that, because of much higher lubricant retaining capability of the microstructured regions, a patterned SLIPS can be simply generated through infusing the lubricant onto the surface and applying a shear spinning process. This work highlights the importance of the dynamics of surface structures to functional materials, showing broad potential applications.