Executive Summary : | Thin-film instabilities due to substrate heterogeneities are a challenge for various applications, but dewetting has emerged as a promising approach for micro/nanoscale pattern formation. Dewetting of thin lubricating films can be used to produce different morphologies, such as micro/nano drops, microchannels, and nanorods, without the need for sophisticated tools. Modulating dewetting patterns using an electric field allows for reversible tuning and control of wetting-dewetting transitions. This study proposes to examine the instability of thin lubricating films on chemically heterogeneous surfaces. The researchers aim to modulate dewetting patterns to achieve directed and ordered patterns with control over size, length scale, morphology, and curvature. They aim to reduce the size of dewetted patterns by an order or more by optimizing various physio-chemical parameters. The study also explores how the surface energy difference between chemical contrast affects the morphology and kinetics of dewetting patterns. Direct observation of the transition from isotropic to anisotropic dewetting via different routes, either through a surface energy gradient approach or external stimulus-triggered dewetting, is also interesting. Dewetting of lubricating films offers flexibility in examining even micrometer thick films, reduces the time corresponding to the onset of the dewetting process, and provides better control. Additionally, using an electric field as an external stimulus allows for tuning pattern formation and observing isotropic to anisotropic dewetting transitions in a reversible manner. Development of these systems involves fabrication of chemically heterogeneous surfaces, lubricant infusion to create uniform lubricant films, and inducing instability in uniform films. |