Executive Summary : | Since the discovery of superhydrophobic behavior in Lotus leaf, various biomimetic surfaces and materials have been studied for their ability to selectively repel water. These surfaces can act as protective barriers and allow precise drop motion. However, they may not demonstrate iceophobic properties due to ice accretion. In high humidity systems, surface-liquid interaction becomes crucial for continuous removal of condensed water drops. The large confinement and surface area facilitate the enhanced rate of condensation, leading to a locked Wenzel State. External force has been used to achieve moving contact lines for drop movement on non-sticking surfaces. However, autonomous drop motion without external force may reduce operation costs. The project aims to fabricate extreme wetting surfaces and study liquid-surface interactions to achieve autonomous drop motion and transport. Smart wetting surfaces with special wetting (supersolvophobic or supersolvophilic) will be fabricated, and liquid-surface interactions through wetting studies will be conducted to understand the contact line behavior of drops on these surfaces. Most work employs water as a solvent for droplet transport, but solvents with low surface tension or high volatility can alter the wettability of extreme wetting surfaces. Surfaces repel common organic solvents and solvents with high viscosity, and how they interact during dynamic wetting will be studied. Recent observations show autophobing without using surface-active agents on atypical surfaces, but the mechanism is still unclear. The project focuses on fabrication and characterization of smart special wettability surfaces, studying drop dynamics, and minimizing energy requirements for droplet motion for cleaning and sensing purposes. |