NIR-driven fast construction of patterned-wettability on slippery lubricant infused surface for droplet manipulation

Abstract Controllable wettability is highly desired for droplet manipulation technology in biomedical system and industry. Here, a photo-responsive slippery surface (G/NPGS) is fabricated based on the silicon oil and graphene composited polymer network. Under near-infrared (NIR) irradiation, the lubricant oil in the bulk of the substrate can be selectively released to the targeted area and then reversibly erased by cooling treatment. Attractively, discretionary patterned-wettability and on-demand droplet-guiding pathway can be constructed within few seconds (5 ~ 10 s). The droplet motion on this surface can be flexibly and spatiotemporally manipulated. The programmable wettability of G/NPGS can not only used for information transmission but also for droplet pipetting, liquid transportation and manipulation in microplates, microfluidics and microreactors. Moreover, the G/NPGS can be applied for photoresist field to replace the developer solution. These findings provide a novel and facile way to rapidly construct programmable wettability, which is highly significant for liquid manipulation, laboratory-on-a-chip settings and microfluidics.