Elastocapillary flow in deformable pdms microchannels

We investigate the elastocapillary flow of Newtonian liquid in rectangular PDMS microchannels having a deformable membrane wall. The inward deflection of the membrane under negative capillary pressure is found to increase the filling speed in horizontal deformable microchannels, and the capillary rise in vertical deformable microchannels. A theoretical model is developed to quantitatively predict these effects, and a non-dimensional parameter J, which represents the ratio of capillary force to the mechanical restoring force, is seen to emerge as an important parameter in quantifying elastocapillary effects. The model predictions show good agreement with experimental data obtained from deformable channels fabricated in PDMS.