J.B. Boreyko
Virginia Tech,
United States
Keywords: bubbles, boiling, droplets, oil-impregnated surfaces
Summary:
We showcase two emerging interfacial phenomena on engineered surfaces. First, we demonstrate the coalescence-induced jumping of micro-bubbles from a superheated surface during pool boiling. By patterning rationally designed microstructures on the surface, bubble nucleation is spatially controlled, which promotes early coalescence events that facilitate capillary-inertial departure. Jumping-bubble-enhanced boiling has the potential to substantively increase the heat transfer coefficient and critical heat flux of boilers. Second, we demonstrate the rapid ziplining of droplets across tilted oil-impregnated nanostructured fibers. It is well known that droplets are slippery on planar oil-impregnated substrates, but the choice of a slender fiber simultaneously exploits the large out-of-plane work of adhesion of the droplet to the oil phase. We expect that linear ziplining could enable long-range droplet transport, droplet sorting, and novel open-air microfluidic platforms.