Overwritable liquid selective open channel

摘要

We fabricated an overwritable liquid channel with liquid selectivity and design flexibility inspired by a coastal animal. The animal has pairs of legs on which open-air capillary structures, what we call open channel, uptake water spontaneously using interfacial free energy. We extracted an essential mechanism controlling this phenomenon and applied it to artificial open channels, aiming at transport and manipulating a variety of liquids without using external energies. 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 lets 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. Copyright (c) 2016 John Wiley & Sons, Ltd.