Facile Fabricating Strategy For Bioinspired Flexible Film With Cavitation: Liquid Super-Repellent Material With Stimulate-Response On Liquid Adhesion

Inspired by liquid super-repellent skin of springtail, air pockets with tiny openings are fabricated on the surface of polydimethylsiloxane (PDMS) to achieve a stable existence of gas between liquid and micro-nanostructure. After further low-energy grafting, the PDMS with air pocket microstructures shows a well hydrophobic and oleophobic property. When the liquid droplet fell on the fabricated surface, the positive pressure generated by the air pocket promotes the wetting state to be much fitting with the Cassie-Baxter model. Based on the super-repellent microstructures, the flexible material shows properties of anti-icing and anti-fog. Additionally, the positive pressure of the air pocket to liquid droplet changed to be negative when stretching stress is applied to the PDMS elastomer. Based on the changed pressure, wetting state of the liquid droplet reversed from super-low adhesion to high adhesion. The stimulus-responsive material with reversible wettability has great potential in the applications of microfluidic chip and controlled releasing liquid micro-droplets.