Enabling microfluidic diagnostic devices using lateral cavity acoustic transducers for on-chip pumping.

摘要

The global drive for the eradication of infectious diseases in developing countries has led to the need for low-cost, highly sensitive, and truly portable diagnostic platforms. Emerging microfluidic technologies have shown great promise, however some components are still lacking the necessary characteristics to enable low-cost and true portability. Specifically, fluidic driving mechanisms are still inconsistent with the micron scale platform. In this dissertation, a novel microfluidic pumping technology is developed from the harnessing of acoustic microstreaming through the use of trapped air bubbles in lateral cavities which are energized through the use of an external acoustic energy source. This technology, called Lateral Cavity Acoustic Transducers (LCAT), is simulated, designed, and optimized to develop an operational design space for future integration into other microfluidic systems. The technology is then integrated into a recirculation immunoassay device for decreased detection times through fluid flow over the binding sites. The recirculation aspects of the design allow for convection limited biomolecule transport using high flow velocities while maintaining low volumes. A 2X gain in signal intensity is realized compared to conventional microfluidic flow-through immunoassay systems.;Finally, further applications of the LCAT technology are demonstrated through proof-of-concept designs for near instantaneous active mixing, particle switching, and particle trapping. These demonstrated applications with the LCAT technology have the potential to improve detection times, sensitivity, and maintain portability with simple integration into existing microfluidic devices.