Mechanisms of Entrapment and Release of Fluid Droplets From Nano-Scale Surface Features

Abstract

Engineering surfaces are never perfectly flat. They contain micro and nano-scale features on multiple length scales. Predicting the amount of fluid trapped in these minute surface crevices and its controlled release could benefit a variety of practical applications. In a sliding contact, the released fluid could create an ultra-thin film, reducing the direct contact and consequently the boundary friction. Transdermal patches are the least invasive of available subcutaneous drug delivery techniques. The drug is stored in a micro-reservoir and it is released to the skin either through a permeable membrane or through a series of micro needles. The aim of the current paper represents the first attempt to investigate whether a modeling approach encompassing two complementary simulation techniques in an integrated framework can be used to predict the volume of fluid stored in a nano-scale surface feature. Molecular dynamics (MD) simulation could provide accurate modeling of fluid behavior at nano-scale, and statistical mechanics (SM) could provide a fast prediction.