A high-shear, low Reynolds number microfluidic rheometer

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.

[1]  D. Weitz,et al.  Tracer microrheology in complex fluids , 1998 .

[2]  S. Quake,et al.  From micro- to nanofabrication with soft materials. , 2000, Science.

[3]  J. Glatz-Reichenbach,et al.  Conducting polymer composites , 1999 .

[4]  Bruce K. Gale,et al.  Determining the optimal PDMS–PDMS bonding technique for microfluidic devices , 2008 .

[5]  S. Kulkarni,et al.  Giant piezoresistive response in zinc–polydimethylsiloxane composites under uniaxial pressure , 2008 .

[6]  G. Whitesides,et al.  Soft Lithography. , 1998, Angewandte Chemie.

[7]  C. Liu,et al.  Recent Developments in Polymer MEMS , 2007 .

[8]  D. Beebe,et al.  Three-dimensional micro-channel fabrication in polydimethylsiloxane (PDMS) elastomer , 2000, Journal of Microelectromechanical Systems.

[9]  Q. Ouyang,et al.  Micro-pressure sensor made of conductive PDMS for microfluidic applications , 2010 .

[10]  P. Arratia,et al.  Microfluidic rheology of soft colloids above and below jamming. , 2010, Physical review letters.

[11]  Kelly M. Schultz,et al.  High-throughput rheology in a microfluidic device. , 2011, Lab on a chip.

[12]  P. Arratia,et al.  Elastic instabilities of polymer solutions in cross-channel flow. , 2006, Physical review letters.

[13]  H. Pak,et al.  Diffusing-wave spectroscopy study of microscopic dynamics of three-dimensional granular systems , 2010 .

[14]  Benjamin C. K. Tee,et al.  Skin-like pressure and strain sensors based on transparent elastic films of carbon nanotubes. , 2011, Nature nanotechnology.

[15]  Gareth H. McKinley,et al.  High shear rate viscometry , 2008 .

[16]  H. Laun.  Polymer melt rheology with a slit die , 1983 .

[17]  L. J. Lee,et al.  High shear microfluidics and its application in rheological measurement , 2005 .

[18]  Paulo E. Arratia,et al.  Stretching and mixing of non-Newtonian fluids in time-periodic flows , 2005 .

[19]  I. Balberg,et al.  Tunneling and percolation in metal-insulator composite materials , 2003, cond-mat/0306059.

[20]  F. C. MacKintosh,et al.  Microscopic Viscoelasticity: Shear Moduli of Soft Materials Determined from Thermal Fluctuations , 1997 .

[21]  Mason,et al.  Optical measurements of frequency-dependent linear viscoelastic moduli of complex fluids. , 1995, Physical review letters.

[22]  Christopher W. Macosko,et al.  Rheology: Principles, Measurements, and Applications , 1994 .

[23]  D. Grier,et al.  Methods of Digital Video Microscopy for Colloidal Studies , 1996 .

[24]  Antony Orth,et al.  Multiplexed pressure sensing with elastomer membranes. , 2011, Lab on a chip.

[25]  P. Arratia,et al.  Undulatory swimming in viscoelastic fluids. , 2011, Physical review letters.

[26]  P. Sheng,et al.  Characterizing and Patterning of PDMS‐Based Conducting Composites , 2007 .

[27]  Wei-Hao Liao,et al.  Integrated ionic liquid-based electrofluidic circuits for pressure sensing within polydimethylsiloxane microfluidic systems. , 2011, Lab on a chip.

[28]  J. Glatz-Reichenbach,et al.  FEATURE ARTICLE Conducting Polymer Composites , 1999 .

[29]  Limu Wang,et al.  Polydimethylsiloxane-integratable micropressure sensor for microfluidic chips. , 2009, Biomicrofluidics.

[30]  A. Palmer,et al.  Diffusing wave spectroscopy microrheology of actin filament networks. , 1999, Biophysical journal.

[31]  G. Whitesides,et al.  Poly(dimethylsiloxane) as a material for fabricating microfluidic devices. , 2002, Accounts of chemical research.

[32]  G. Whitesides,et al.  Microfluidic devices fabricated in Poly(dimethylsiloxane) for biological studies , 2003, Electrophoresis.

[33]  Steven T. Wereley,et al.  Design, fabrication and characterization of a conducting PDMS for microheaters and temperature sensors , 2009 .

[34]  Ronald G. Larson,et al.  A purely elastic instability in Taylor–Couette flow , 1990, Journal of Fluid Mechanics.