Topography-Free Dual-Lubricant Patterned Slippery Surfaces for Programmable Droplet Control and High-Performance Water Harvesting.

Passive droplet control is critical for next-generation water harvesting, fluidic logic, and adaptive wetting surfaces. Here, we report a scalable, topography-free slippery liquid-infused porous surface (SLIPS) based on poly[1-phenyl-2-[p-(trimethylsilyl)phenyl]acetylene] (PTMSDPA). By selectively chemically fluorinating specific regions of the porous PTMSDPA film, followed by sequential infusion of two immiscible hydrophobic lubricants into their respective affinity-matched polymer matrices, this approach enables interfacial energy contrasts that direct droplet motion. The heterogeneous oil-infused porous surface (HOIPS) has a unique intrinsic fluorescence enabling real-time, dye-free visualization of infiltrated lubricant domains. Owing to its ultrathin (∼200 nm) and flexible polymer structure, the HOIPS enables controllable droplet motion on flat, flexible, and curved substrates without reliance on surface topography, physical confinement, or asymmetric geometries. Sub-millimeter-scale HOIPS line patterns enable controlled droplet coalescence, shedding diameter, and release timing during condensation, and optimized patterns exhibit up to 2.5× higher water-harvesting performance compared to fluorinated-oil-based SLIPS, providing a material-efficient strategy for liquid-repellent surfaces. Taken together, these results establish PTMSDPA-based HOIPS as a versatile platform for controlled droplet manipulation and condensation management.