Microfluidic channels of adjustable height using deformable elastomer

In the emerging field of deformable microfluidics, we propose a new geometry in which the height and angle of a channel are controlled, thanks to the deformability of the microfluidic elastomer down to thicknesses of a few microns. The particularity of our set-up is that the height of the channel under study is fully closed at rest, which reveals especially well suited to address micro-nanoconfinement problems such as clogging, transport selectivity and flow rectification. Using fluorescence microscopy and light absorption, we probe the channel shape from the measurement of the PDMS-displacement field. We demonstrate that the maximal PDMS displacement can be inferred from finite elements numerical simulations and predicted reliably with simple analytical relations from elasticity continuum mechanics.