Enhanced Imbibition in Liquid-Infused Coated Microchannels.

Spontaneous capillary imbibition has the potential to improve the performance of many micro and nanodevices since it does not require an external energy source to drive a fluid flow. Despite this advantage, controlling and reducing the friction exerted by the channel walls, which limits the speed of the liquid, remains a challenge. Here, we demonstrate experimentally that infusing the walls of a channel with a liquid lubricant substantially speeds up the imbibition process and reduces the overall viscous friction. By varying the viscosity of the lubricant, we observe a substantial reduction of the imbibition time of up to 50%. Our experimental results are in good agreement with previous theoretical predictions, providing a solid framework to study low-resistance spontaneous imbibition processes.