Diffusion-Limited Evaporation in Long Microchannels

Abstract

The evaporation of liquids confined to long, shallow microchannels is studied experimentally. Channels with dimensions 5 microns high, 100 microns wide and approximately 9000 microns long are filled with a liquid and then allowed to dry out due to evaporation through ports at both ends of the channel. The slug of fluid is observed to shrink at a rate that is, after some adjustment time, found to be linearly depend on the inverse of the meniscus position. In case of the water, the contribution of film flow in the microchannel evaporation is found to be larger than ethanol. But the surfactant cannot make much difference on the microchannel evaporation.