Differential capillary viscometer for measurement of non-Newtonian fluids

Here we demonstrate a novel differential microfluidic device for the determination of the rate dependence of the shear viscosity of complex fluids. The device design is simple, robust and does not require internal or external pressure measurements, making the method open for miniaturisation and incorporation into lab-on-a chip applications and online monitoring purposes in process control. The working principle is tested in several possible geometries with different shear thinning model fluids with power-law exponents n ranging from 0 < n < 1.