Molecular diffusion replaces capillary pumping in phase-change-driven nanopumps

摘要

Inspired by the capillary-driven heat transfer devices, we present a phase-change-driven nanopump operating almost isothermally. Computational experiments on different-sized nanopumps revealed efficient operation of the pump despite the reduction in system size that extinguishes capillary pumping by annihilating the liquid meniscus structures. Measuring the density distribution of liquid near evaporating and condensing liquid/vapor interfaces, we discovered that phase-change-induced molecular-scale mass diffusion mechanism replaces the capillary pumping in the absence of meniscus structures as long as the liquid wets the walls of the capillary conduit. Therefore, proposed pumps can serve as a part of both nanoelectromechanical and microelectromechanical systems with similar working efficiencies.