Smart Multiple Wetting Control on ZnO Coated Shape Memory Polymer Arrays

Recently, surfaces with intelligent wetting controllability have aroused increased attention. Endowing the surface with stimuli-responsive surface chemistry and tunable surface microstructure can achieve a surface with smart wetting performances. However, almost all existing surfaces only focused on single surface chemistry or micromorphology, thus to achieve smart multiple wetting regulation is still difficult. Herein, we report a ZnO coated shape memory polymer(SMP) surface, and the surface chemistry and micromorphology can be synergistically regulated. ZnO can provide adjustable surface chemistry under UV irradiation, and SMP can offer tunable micromorphology due to its shape memory effect(SME). Based on the combined effect between the above two features, surface wetting performance can be smartly regulated among multiple states. Moreover, due to the excellent controllability of the surface, the application in directional droplet transportation was also demonstrated. This paper offers a new surface with tunability in both surface chemistry and micromorphology, and given the excellent wetting controllability, the surface is believed to be applied in a lot of fields, such as droplet manipulation, fluidic devices and selective catalysis.