Mechanically Tunable Superhydrophobic Surfaces Enabled by the Rational Manipulation of Microcrack Networks in Nanoporous Films

Adaptive materials with tunable superhydrophobic surfaces promise to impact a range of fluid handling technologies; however, adaptive superhydrophobic materials remain difficult to fabricate, control, and switch rapidly. Here, a versatile method for generating hierarchically structured and adaptive superhydrophobic silicone films for the rational control of surface wettability and droplet adhesion is reported. Specifically, mechanical tension is utilized to manipulate networks of microcracks in nanoporous layers supported on elastomeric silicone films, enabling dynamic modulation of superhydrophobicity and droplet adhesion. The reported mechano-responsive superhydrophobic surfaces are applied to directional droplet shedding and "no-loss" droplet transport and are used to generate artificial "skins" with droplet tweezing capabilities. This approach provides materials with enhanced functionality useful to a range of emergent technologies, including adaptive textiles, biocompatible (wearable) sensors, soft robotics, anti-icing systems, "no-loss" droplet manipulators, and thermal management devices.