Noninvasive acoustic-wave microfluidic driver

This paper describes a noninvasive acoustic-wave microfluidic driver built on a PZT sheet. The driver is based on the acoustic streaming effect and the self-focusing nature of the Fresnel Annular Sector Actuator (FASA). An array of FASAs is produced on a PZT sheet, and set adjacent to a silicon wafer to produce a fast liquid motion (up to 123 mm/s) in a 0.8 mm wide, 9 mm long and 0.2 mm deep channel in silicon. The self-focused waves from the FASA array propagate through the 200 /spl mu/m thick silicon, and act on the water contained in the channel. Three kinds of FASA arrays have been fabricated along with their associated channel structures in silicon, and shown to transport the liquids effectively. The experimental results obtained on the fabricated devices confirm the theory and simulation.