In the project, I am working on different static and dynamic wetting morphologies on different structured substrates. Static wetting morhologies are created by manipulating the wetting property (by coating the substrates with self-assembled monolayers) and evaporating short chain polystyrene (~2kg/mol). Dynamic wetting properties are obtained using electrowetting.
Substrates used for electrowetting experiment are coated with thick dielectric layer (in my case 1�m SiO2). By applying the electric field, charge accumulation in this dielectric layer changes the surface property ad thus contact angle. Using the electrowetting effect, we explore the transport of liquids on a substrate bearing appropreate steps and grooves, by switching between various different morphologies of the free liquid surface. The particular advantage of the topographic substrate is the variability of the Laplace Pressure of the emerging liquid morphologies, such that the liquid may be taken even from a zero pressure reservoir. We study the impact of variety of parameter such as the amplitude of the applied (-ac) voltage, its frequency, the thickness of the oxide layer, conductivity of the liquid and the topography of the substrate. The liquid morphologies are observed using Atomic Force Microscopy (AFM), optical (fluoroscence) microscopy and confocal microscopy.