Liquid morphologies on structured surfaces: From microchannels to microchips

Liquid microchannels on structured surfaces are built up using a wettabilit y pattern consisting of hydrophilic stripes on a hydrophobic substrate, The se channels undergo a shape instability at a certain amount of adsorbed vol ume, from a homogeneous state with a spatially constant cross section to a state with a single bulge. This instability is quite different from the cla ssical Rayleigh Plateau instability and represents a bifurcation between tw o different morphologies of constant mean curvature. The bulge state can be used to construct channel networks that could be used as fluid microchips or microreactors.