Multiphase microfluidics utilizes water-in-oil droplets as vessels for chemical reactions. With volumes of nL-pL, they can provide reaction volumes one million-fold smaller than conventional microplates, enabling new experimental approaches for high-throughput chemistry and biology. In order to leverage these benefits, one must be able to perform conventional fluid handling operations in the droplet format. Multiphase microfluidics is considerably more complex than single phase flow, as it involves multiphase flow interactions, interfacial tension, Laplace pressures, interfacial adsorption, and other phenomena acting in cohort with laminar flow. Rather than work against these phenomena, we exploit them in novel ways in order to perform key fluid handling and sensing operations.
This talk will discuss several such technologies being explored in our group:
- the formation of heterogeneous droplet screening libraries using microfractionation-in-droplets (µFD);
- Concentrating particles in plugs, exploiting hydrodynamic microvorticesand sedimentation inherent to plug flow;
- Light-based manipulation of droplets using optofluidictweezers (OFT), a novel technique which uses laser-induced thermocapillarymicrovorticesto trap droplets with µN forces (100,000X larger than traditional optical tweezers);
- Sorting droplets by size using tensiophoresis, the cross-stream migration of droplets in an interfacial tension (IFT) gradient; and
- Detecting femtomolesof proteins in droplets using interfacial adsorption phenomena. Experimental and computational methods will be discussed.
Amar Basu received a BSE and MSE in electrical engineering in 2001 and 2003, an MS in biomedical engineering in 2005, and a Ph.D. in electrical engineering in 2008, all with honors from the University of Michigan Ann Arbor. His dissertation work, under Prof. Yogesh Gianchandaniat the NSF Center for Wireless Integrated Microsystems, investigated interfacial-tension based fluid actuators. Amar worked with Intel's Advanced Technology group, General Motors, Silicon Graphics, and served as an adjunct faculty at the University of Michigan. He is currently associate professor of electrical engineering and biomedical engineering at Wayne State University. His research, supported primarily by the NSF, focuses on microfluidic and microelectronics for high throughput screening and point of care monitoring. Amar received the NSF BRIGE award in 2009, WSU College of Engineering Outstanding Faculty Award in 2013, the IEEE-WSU Professor of the Year (voted by students) in 2009, and the Whitaker Foundation Fellowship in 2003. His research and consulting work has resulted in 9 issued or pending patents.
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Room 2001, Birck Nanotechnology Center, Purdue University, West Lafayette, IN