Measuring the viscosity of chemical and biological fluids is an important analytical tool in applications ranging from medical diagnostics and research to the chemical and manufacturing industry. The viscosity of body fluids such as blood, blood plasma, amniotic, and synovial fluid plays an important role in diagnostic, prognostic, and preventive medicine. While quick measurement of viscosity at the point of specimen may provide immediate insight into the physiological state of the patient, most current viscometers are designed predominantly as benchtop instruments. Accordingly, there exists a need for a viscometer that is inexpensive and uses low sample volumes that are, in particular, suitable for biological and medical applications.
Researchers at the University of Michigan have developed a microfabricated, microfluidic viscometer which operates on very small sample volume. The device is based on a nanoliter capillary viscometer which determines fluid viscosity by monitoring the progress of liquid through a channel. In addition, the microfabricated viscometer operates entirely through capillary pressure generated within microfluidic channels without the need for external actuation. A wide range of shear rates may be obtained with the microfabricated viscometers by appropriately changing the geometry and dimensions of the microfluidic channels. Moreover, the microfabricated viscometers of the invention are useful for measuring the viscosity of both Newtonian and non-Newtonian fluids, and viscosities in the range of 1 cP to 1000 cP are easily measured.
Applications and Advantages
- medical diagnostics
- chemical and manufacturing industry
- any application in which rapid viscosity-nl-measurements based on small sample volume-nl-are desired
- manufactured using standard photolithographic-nl-methods/ simple fabrication
- easy to use
- no moving parts
- provides rapid viscosity measurements
- requires minimal sample volume (