A single channel capillary microviscometer

Abstract

We have developed a microviscometer analyzing the fluid dynamics in a single channel glass microfluidic chip with a closed end. The device is able to test sample volumes of a few microliters by inserting one drop in the inlet. The fluid enters the channel driven by capillary pressure and an optical sensor registers the motion. The equation that describes the fluid dynamics is function of the channel geometry, atmospheric pressure, fluid viscosity, and capillary pressure. Knowing the first two, the last parameters can be obtained as fitting parameters from the meniscus position as a function of time plot. We have successfully tested Newtonian fluids with different viscosities and capillary pressure.