We present how to make and assemble micro-patterned stickers (microPS) to construct high performance plastic microfluidic devices in a few minutes. We take advantage of soft UV imprint techniques to tailor the geometry, the mechanical properties, and the surface chemistry of 2D and 3D microfluidic circuits. The resulting microfluidic stickers substantially overcome the actual performance of the very popular PDMS devices for a wide range of applications, while sharing their celebrated fast and easy processing. To highlight the intrinsic advantages of this method, three important applications are detailed: (i) we show that both aqueous and organic droplets can be produced and stored in stickers without any specific surface coating. (ii) We report on the outstanding pressure resistance of the microPS, which open the way to the transport of viscous complex fluids. (iii) Finally, a simple design strategy is proposed to generate complex flow patterns in interconnected stacks of microPS.

We image the flow of complex fluids in microchannels of controlled geometry using tracers. The spatial resolution allows us to access quantitatively the bulk nonlinear rheology and wall slip, as we show on model polymer solutions. In perspective this strategy should prove useful for the study of heterogeneous flows of more complex fluids.

We characterize heterogeneous flows of a wormlike micelles solution in microchannels. Combining a pressure resistant microfabrication technology and a performant particle image velocimetry setup, we succeed in determining the nonlinear rheology of this fluid over 4 decades in shear rate and in particular more than 1 decade beyond the end of the stress plateau. We performed an independent measurement of the slip length with 1 μm resolution.