Research Projects

Dewetting refers to the process of a thin film of liquid breaking up into separate droplets or withdrawing from a surface to form droplets. This phenomenon can occur due to various reasons, such as the chemical nature of the substrate, temperature, and external forces like electromagnetic fields, gravity etc. Dewetting is a critical issue in many industrial and technological applications, including coating, printing, and microfabrication. The dewetting process can cause defects and reduce the quality and performance of the final product. Therefore, instability or dewetting of liquid films which earlier was only considered as undesirable phenomena, which though had a rich and complex surface science yet no applied aspects, nowadays, has been explored as a tool for micro/nano-patterning, investigating interfacial phenomenon, etc. Researchers have studied dewetting extensively to understand the underlying mechanisms and develop strategies to prevent or control it. This involves exploring the interfacial energy between the liquid and substrate, the effects of surface roughness and topography, and the role of various external factors. Stable thin liquid films can be destabilized using different stimulus i.e. mechanical vibrations, electric or magnetic forces and temperature induced fluid flow. Added thrust with external stimulus induced dewetting is that the wetting behavior can be reversible tuned on demand which would greatly benefit the microfluidic industry. Inspired by Nepenthes Pitcher plant, thin lubricating films of Slippery Liquid-Infused Porous surfaces (SLIPs) is one of the best system to investigate the stability and dewetting of thin liquid films. Compared to conventional dewetting studies, where films are prepared in non-equilibrium in air, thin lubricating films on slippery surfaces are prepared in equilibrium and can be stabilized or destabilized based on various interfacial energies across the film. This is unique system which allows to investigate dewetting in using an external stimuli e.g. electric field. In this research, we propose to investigate stability criteria of lubricating films and will explore different routes to destabilize the film; by introducing heterogeneity to the surface and using electric field as an external stimulus to induce instability. Heterogeneity based dewetting would only allow us to investigate the dewetting in an irreversible manner, whereas using electric field as an external agent would rather allow to investigate wetting-dewetting transitions in a reversible and reproducible manner.