Interfaces between a water droplet and a network of pillars produce eventually superhydrophobic, self-cleaning properties. Considering the surface fraction of the surface in interaction with water, it is possible to tune precisely the contact angle hysteresis (CAH) to low values, which is at the origin of the poor adhesion of water droplets, inducing their high mobility on such a surface. However, if one wants to move and position a droplet, the lower the CAH, the less precise will be the positioning on the surface. While rigid surfaces limit the possibilities of actuation, smart surfaces have been devised with which a stimulus can be used to trigger the displacement of a droplet. Light, electron beam, mechanical stimulation like vibration, or magnetism can be used to induce a displacement of droplets on surfaces and transfer them from one position to the targeted one. Among these methods, only few are reversible, leading to anisotropy-controlled orientation of the structured interface with water. Magnetically driven superhydrophobic surfaces are the most promising reprogramming surfaces that can lead to the control of wettability and droplet guidance.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.