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|Author(s):||Gordon Christopher; Jae M. Yoo; Nicholas G. Dagalakis; Steven D. Hudson; Kalman D. Migler;|
|Title:||Development of a MEMS based Dynamic Rheometer|
|Published:||August 31, 2010|
|Abstract:||Rheological methods that interrogate nano-liter scale volumes of fluids and solids have advanced considerably over the past decade, yet there remains a need for methods that probe the frequency dependent complex rheological moduli through application of homogenous strain fields. Here we describe a Micro-Electro-Mechanical System (MEMS) based approach for the measurement of dynamic rheology of soft matter where oscillatory strain is produced in a sample sandwiched between an oscillating MEMs stage and a glass plate. The resulting stress-strain relationships are revealed by measurement and analysis of the stage motion. We present preliminary data on simple viscous fluids and on viscoelastic thin films. In this proof-of-principle device, we measure moduli in the range of 50 Pa to 10 kPa over a range of 3 - 3000 rad/s using less than 5 nL of sample material; the device s measurement window is limited primarily by our current ability to measure the motion of the stage. This device will provide a new way to characterize dynamic microrheology of an array of novel materials that will prove useful in a number of areas including biorheology, microfluidics and polymer thin films.|
|Citation:||Lab on A Chip|
|Pages:||pp. 2749 - 2757|
|Keywords:||Microrheology, complex fluids, soft matter, MEMS|
|Research Areas:||Complex Fluids|
|PDF version:||Click here to retrieve PDF version of paper (305KB)|