We report ultrafast control of phase-change based microvalves utilizing nanoheaters; ferronanoparticles dispersed in paraffin wax, and heating by optical illumination using a 808 nm laser diode. High speed camera images showed that the actual response time to open the normally closed microvalve was only 0.012 sec at 46 kPa and to close the normally opened microvalve was only 0.444 sec. We further demonstrated sequential operation of multiple microvalves on a centrifugal microfluidic device using single laser diode. To the best of our knowledge, it is the first to use optical excitation of nanoparticles for the mechanism of microvalve operation. Because it is fast, robust, cost-effective, biocompatible, and simple to implement for the control of multiple microvalves on a chip, we believe it could be a key component to realize fully integrated lab-on-a-chip devices.
Journal: TechConnect Briefs
Volume: 3, Technical Proceedings of the 2007 NSTI Nanotechnology Conference and Trade Show, Volume 3
Published: May 20, 2007
Pages: 308 - 311
Industry sector: Sensors, MEMS, Electronics
Topics: Micro & Bio Fluidics, Lab-on-Chip