View Generic Document: Chaotic Mixing in Microfluidic Devices
Citation:
Hughes, Nicholas (2005). Chaotic Mixing in Microfluidic Devices. National Institute of Standards and Technology, Technology Administration, U.S. Department of Commerce..
Microfluidic flows are normally low Reynolds number (Re) due to the very small length scales at which these devices are fabricated. This makes turbulent flow virtually impossible to
achieve and the mixing of fluids is generally slow and diffusion controlled. Mixing can be greatly enhanced in the laminar flow regime by subjecting the fluid to chaotic flow kinematics. In chaotic
advection, material lines undergo complex patterns of stretching and folding. Mixing is greatly enhanced both by the tendency of fluid particles to become homogeneously dispersed, and by a decrease
in the length scale for diffusion between unlike components. In this work, mixing in microfluidic devices in which flow in the streamwise direction is perturbed by oscillatory transverse flow has
been studied. Numerical simulation of the unsteady Navier-Stokes equations has been used to determine combinations of flow geometries and boundary conditions which lead to chaotic mixing regimes.
The flows are shown to be chaotic by the computation of positive Lyapunov exponents and by visual inspection of particle scatter when material lines undergo stretching and folding. A number of
cases that show promise for future experimental work will be shown.
Publisher
National Institute of Standards and Technology, Technology Administration, U.S. Department of Commerce.
Guest - January 07, 2009
View Generic Document: Chaotic Mixing in Microfluidic Devices 