Hiroki Kuwano
Tohoku University, Japan
Title: Micro/nano fluid handling system using surface acoustic wave
Biography
Biography: Hiroki Kuwano
Abstract
Micro/nano fluid handling system using surface acoustic wave (SAW) is described for medical/bio, chemical synthesis; analysis and so on. We developed an atomizer and micro pump using SAW for a converged mist spray with a sustained liquid supply mechanism. The atomizer can produce a narrow mist spray of sub-millimeter width. The atomized mist spray converges spontaneously and thus requires no additional spray converging system. Key features in achieving the self-converging atomization are two-port interdigital transducers (IDTs) with a groove in between. The SAW is driven by applying an electric field on IDTs patterned on a piezoelectric substrate. The two-port IDTs drive SAWs in opposite directions toward the groove, which then separates the SAW-driven streaming on each side of the groove. Two types of self-converging atomizer were experimentally demonstrated, a line and a point atomizer. While the former uses parallel IDTs to atomize water from the groove into a thin-planar-shaped spray, the latter uses arc-shaped SAW lenses to focus the SAW into a certain point in the groove to atomize water into a narrow point spray. The developed micropumps consisted of an epoxy-based reservoir with an exhaust slot and a pair of interdigital transducers (IDTs). The liquid supply from the reservoir was controlled by SAW bursts from the IDTs. A micro tank was fabricated into the exhaust slot to stabilize the atomization. In the operational test of the micropump with water, a transfer rate of 0.24 pl per single burst was confirmed.