Pulsatile Flow in Microfluidic Networks with Passive Deformable Features

Featuring Matthew R. Begley, Ph.D.

Professor, Mechanical Engineering

University of California, Santa Barbara



Free and open to the public



Abstract:

The elimination of externally controlled valves that guide flow in fluidic microchips remains a persistent obstacle to constructing truly portable, inexpensive bioanalytical diagnostics.  This talk will describe the physics of fluid flow in microfluidic devices with deformable features, which exploit  solid/fluid coupling to control flow. It will be shown that dynamic flow characteristics in such networks can be predicted using elementary models of solid and fluid behaviors, which greatly facilitates the design of networks with specific flow responses. Experimental results will be presented which illustrate flow switching in a branched network without the use of externally activated valves. The advantages and challenges of exploiting low-amplitude, high frequency actuation to simplify flow in diagnostic microchips will be briefly discussed.  The talk will conclude with an interesting similarity between chips with deformable features and pulsatile swimmers such as salps and squid; the above models will be used to illustrate that swimming economy (distance traveled per unit input work) and device efficiency (useful output work per unit input work) are optimal at different pumping frequencies.



About the Speaker:

Matthew R. Begley, Ph.D., recently joined UCSB as a professor of mechanical engineering in 2010. Begley is widely recognized for work that quantifies the performance of thin films and coatings, including experiments, analytical solutions and computational mechanics.  His work in microelectronics and MEMS has recently shifted towards microfluidics and physical chemistry, with an emphasis on dynamic flow behaviors and surface adsorption of nucleic acids. Begley is currently an associate editor of the ASME Journal of Applied Mechanics, and serves as the co-director of the Institute for Collaborate Research at UCSB.