Reversible Structure Engineering of Bioinspired Anisotropic Surface for Droplet Recognition and Transportation

ABSTRACT: Abstract Surfaces with tunable liquid adhesion have aroused great attention in past years. However, it remains challenging to endow a surface with the capability of droplet recognition and transportation. Here, a bioinspired surface, termed as TMAS, is presented that is inspired by isotropic lotus leaves and anisotropic butterfly wings. The surface is prepared by simply growing a triangular micropillar array on the pre?stretched thin poly(dimethylsiloxane) (PDMS) film. The regulation of mechanical stress in the PDMS film allows the fine tuning of structural parameters of the micropillar array reversibly, which results in the instantaneous, in situ switching between isotropic and various degrees of anisotropic droplet adhesions, and between strong adhesion and directional sliding of water droplets. TMAS can thus be used for robust droplet transportation and recognition of acids, bases, and their pH strengths. The results here could inspire the design of robust sensor techniques. The dynamic tuning of the wetting state of a droplet on a surface is realized by an asymmetric surface microstructure and mechanical stress. The proposed surface, TMAS, can switch in situ between isotropic and various degrees of anisotropic adhesions to water droplets, and can be used for the robust transportation of droplets and the recognition of acids, bases, and their pH strengths. TMAS shows the capability of in situ reversibility and fast response, demonstrating the future applications for sensor techniques.

SUBMITTER: Li Q 

PROVIDER: S-EPMC7509748 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature