m-VROC II Viscometer

m-VROC II is the next generation of leading semi-automated, small sample viscometer. Capable of the most demanding applications including small sample protein therapeutics, m-VROC II features the widest dynamic range (high shear rate viscosity measurements up to 2,020,000 s^-1) with as little as 15 microliters of sample.

Understanding Fluid Behavior — Measuring Absolute Viscosity

With VROC^® Technology, RheoSense took the standard principles of rheometry and created a dynamic micro-sample viscometer by adding microfluidics while reducing the size of the device with MEMS (micro-electrical mechanical systems) manufacturing. The result was a new platform which offers capabilities that are well beyond the limits of conventional viscometers in not only the sample volumes required, but the measurement range and precision.

Scientific Principle

The measuring cell or “chip” contains a rectangular slit flow channel constructed of borosilicate glass, with a uniform cross-sectional area. The sample is injected at a constant flow rate though the flow channel where multiple pressure sensors mounted within the base monitor the pressure drop from the inlet to the outlet. The pressure drop is correlated with the shear-stress at the boundary wall. The shear rate and shear stress are directly related to the geometry of the rectangular slit and the flow rate which allow for viscosity measurements.