Patent ID: 7040144
Filing Date: 2006-05-09
Classification: B01L,G01N,G05D

Abstract:
1. A method for determining a relative viscosity of a sample fluid and a reference fluid, the method comprising: (a) establishing a steady flow of the reference fluid through two microfluidic channel segments of different hydrodynamic resistance, a first microfluidic channel segment and a second microfluidic channel segment, each of the two microfluidic channel segments having an inlet and an outlet; (b) introducing a detectable perturbation into the steady flow of reference fluid at the inlet of each of the two microfluidic channel segments at a first time; (c) measuring a first transit time that transpires from the first time until the detectable perturbation exits the outlet of the first microfluidic channel segment; (d) measuring a second transit time that transpires from the first time until the detectable perturbation exits the outlet of the second microfluidic channel segment; (e) calculating a difference in the first and second transit times for the reference fluid; repeating steps (a)–(e) with a sample fluid, thereby determining a difference in the first and second transit times for the sample fluid; and determining a relative viscosity of the sample fluid by comparing the difference in the first and second transit times for the reference fluid and the difference in the first and second transit times for the sample fluid.