| Recently AC electroosmosis has emerged as a promising strategy to capture, manipulate and transport bio/nano-particles in microfluidic devices. This presentation focuses on new development of AC electroosmosis by adding a bias to induce asymmetric electrode polarization. Using an array of microfabricated planar interdigitated electrodes, the electroosmotic flows and particulate assembly patterns on electrode surface are examined. As the electroosmotic device involves no moving parts, it is simple and reliable, which makes it an excellent candidate for microsystem integration.; Two topics are studied in this research. One is the trapping/concentration of colloidal and bio-particles. Particle trapping is conducted over an electrolyte/electrode interface of a gold (Au) electrode pair. We have developed the capability to integrate AC electroosmotic particle trap on the micro-cantilever (MC) in a microfluidic system. The second topic is the transport/mixing of fluids. An original biased AC electroosmotic pump is being developed, and experiments have been performed to prove the concept. Both numerical simulation and pumping experiment is done to increase the surface velocity. Future development of ACED lab-on-a-chip will also be discussed. |
