A high-shear, low Reynolds number microfluidic rheometer
- 879 Downloads
We present a microfluidic rheometer that uses in situ pressure sensors to measure the viscosity of liquids at low Reynolds number. Viscosity is measured in a long, straight channel using a PDMS-based microfluidic device that consists of a channel layer and a sensing membrane integrated with an array of piezoresistive pressure sensors via plasma surface treatment. The micro-pressure sensor is fabricated using conductive particles/PDMS composites. The sensing membrane maps pressure differences at various locations within the channel in order to measure the fluid shear stress in situ at a prescribed shear rate to estimate the fluid viscosity. We find that the device is capable to measure the viscosity of both Newtonian and non-Newtonian fluids for shear rates up to 104 s−1 while keeping the Reynolds number well below 1.
KeywordsRheometry Microfluidics Low Reynolds number flows High shear rates Non-Newtonian fluids
- Larson RG (1999) The rheology and structure of complex fluids. Oxford University Press, OxfordGoogle Scholar
- Macosko CW (1994) Rheology principles, measurements, and applications. Wiley-VCH, WeinheimGoogle Scholar
- Shen XN, Arratia PE (2011) Undulatory swimming in viscoelastic fluids. Phys Rev Lett 106:208,101Google Scholar