Improvement of superhydrophobic properties of soft materials based on surface texture design

Superhydrophobic surfaces of rigid materials have been widely studied, which usually have excellent physical properties. However, the soft materials are rarely investigated. In order to explore ways to improve the superhydrophobic properties of soft materials, different textured structures were fabricated by the inverted molding method on three materials, including food-grade silica gel, industrial-grade mold silica gel, and Polydimethylsiloxane (PDMS). Further, a series of experiments were carried out, including water contact angle measurement, self-cleaning test, and drop-bounce test. The results show that hydrophobicity is highly related to both material and texture characteristics. For the same material, the contact angle can be greatly improved by surface micro-texture, and the contact angle of PDMS can be increased to 159.3°. Moreover, texture features and parameters are introduced to quantitatively analyze the contact angle of textured soft materials. It can be predicted that the soft materials with textured superhydrophobic properties will have greater applications in biomedicine, bionic sensors, flexible solar cells, and other fields.