PS-6 Theoretical and Experimental Study of A High Flow Rate Ultrasonic Horn Pump

This work investigates a liquid pump formed by a silicon ultrasonic horn that can pump fluid from tip of the horn to the shank end of the horn through an internal channel, when the horn is actuated at its half-wavelength longitudinal mode. The pumping rate increases with actuating voltage and decreases with the fluid's viscosity. Water flow rate as high as 9.9 mL/min at 28 V_pp actuating voltage was measured, for a microchannel with cross-sectional area of 0.177 mm ². Nonlinear acoustic streaming phenomena generated by the high velocity vibration of the horn is studied analytically and experimentally, to illustrate the interaction between the vibrating structure and fluids, and to gain understanding of the pumping mechanism. The microfabricated silicon horn pump has no complicated moving parts and is self priming. The fluid being pumped is not subject to electrical or magnetic fields, making the ultrasonic horn pump an appealing candidate for fluid sampling in microfluidic devices