Liquid manipulation is very important for micro and nano fluidic devices and an intelligent bio interface. Micro droplet transfer on high adhesion superhydrophobic surfaces has been reported in recent years. By using the superhydrophobic metal−polymer co-existing surfaces possessing different adhesion properties, micro droplet transfer between superhydrophobic surfaces was achieved. Water micro droplets were transferred from a low-adhesion superhydrophobic surface to a middle-adhesion superhydrophobic surface via a high-adhesion superhydrophobic surface without any mass loss. Droplet after transferring possessed high water contact angle over 150°. These moving processes were performed repeatedly. These droplet handlings on the adhesion superhydrophobic surfaces will be expected for fluidic devises with energy saving.
Water transport was achieved by using open channel with liquid selectivity and design flexibility inspired by a coastal animal. The animal has pairs of legs on which open-air capillary structures uptake water spontaneously using interfacial free energy. After surface modifications, the artificial open channels were able to transport a variety of liquids against gravity by the synergetic effect of surface chemistry and structure, and the surface energy contrast induced by partial modifications let a certain liquid spread through on specific areas of the channel. In addition, these wetting properties and shapes of the liquid channels were found to be overwritten over multiple times with a set of surface modifications. These rewritable open channels with liquid selectivity are applicable to a wide variety of microstructure surfaces, opening the way for its application of reusable microfluidics and lab-on-a-chip devices.