Pervaporation-induced drying in networks of channels of variable width

We study the influence of variations cross-section on drying dynamics by pervaporation in microfluidic channels surrounded water-permeable polydimethylsiloxane (PDMS) walls. Single linearly increasing and decreasing width display similar time, but different towards final drying. with stepwise or show jumps velocity when meniscus separating water-filled dry part channel crosses steps. In branched networks, narrower branches tend to faster than wider ones. All these observations are rationalised framework a model based solution diffusion equation water through PDMS, accounting precisely for local geometry, provided section variation is slow. This shows that depends strongly at location. It captures quantitatively our measurements, except magnitude Implications perspectives this discussed context leaf so-called air seeding mechanism trees.