(Sensors, Materials for Advanced Research in Renewable-energy and Technology)
Instability and dynamics of ultrathin (< 100 nm) films engendered by the intermolecular forces or by substrate wettability gradient have been extensively studied in recent times owing to their potential in the nanostructure formation. Functional coatings of ultrathin films for protection, heat and mass transfer, or adhesives are found to be spontaneously unstable under the influence of van der Waals forces. Further, the functional surfaces are very often decorated with physic-chemical patterns for the technological needs.
The thin protective coatings can also be unstable owing the presence of these spatial wettability gradients on the surface. Interestingly, the instabilities of ultrathin films generate exotic mesoscale structures, which also have technological importance in fabricating super-hydrophobic surfaces, micro/nano fluidic devices, MEMS, NEMS, and drug delivery modules. In addition, the stability/ instability of ultrathin films also uncovers a host of interesting features of a number of scientific issues such as intermolecular force, wetting/dewetting, adhesion/debonding, friction/slippage, phase transition, adsorption, and finite-size effects. Thus, extensive research efforts have been invested in the recent past to uncover the key features of the stability or instability of the ultrathin (< 100 nm) films. The previous studies indicate that ultrathin bilayers show richer varieties of interfacial morphologies important for fabricating embedded and encapsulated structures, which is otherwise impossible involving thin single layers. Presently, we are planning to explore computationally various scientifically interesting and technologically important interfacial morphologies employing ultrathin bilayers. We ae using computational fluid dynamics, molecular dynamic simulations, and various analytical methods to study explore various interesting aspects of these systems.