Bioinspired programmable wettability arrays for droplets manipulation

Significance Droplet manipulation has received great attention and research for its potential applications in various fields. Wettability surfaces, especially tunable wettability surfaces, are efficient way to manipulate the pinning and sliding of droplets. However, these surfaces only demonstrate uniform wettability control behavior and thus were difficult to accurately manipulate droplets to a certain location or multiple locations. In this paper, inspired by the microstructure of stomata distributed on plants, we present programmable wettability arrays for droplets manipulation by using microfluidic emulsification templates. Based on the intelligent composite system, controllable droplet sliding on programmable wettability pathways and effective droplet transfer for printing with mask integration have been demonstrated.