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This paper presents acoustic propulsion in air by synthesis jets produced by ultrasounds. Various ultrasonic air-borne propellers have been fabricated on 0.37-mm-thick commercial card piezoelectric speakers (APS2513S-T-R, 25.2 × 16.6 × 0.37 mm3 in size), and studied, with the propulsion force measured through a precision weight scale, as the orifice size, thickness, spacing between orifices, and number (in the orifice array) are varied. Also varied is the orifice depth profile, as the fabrication processes for the orifices produce varying profiles. Strongest acoustic propulsion of 5.4 mg is obtained at 66 kHz (far beyond audible range) with 14 × 14 orifice array made on a 0.1-mm-thick polyester plate (resulting in a propeller of 25.2 × 16.6 × 1.37 mm3 in volume and 500 mg in weight). The acoustic propulsion force, though 93 times less than the propeller weight, is capable of making the propeller jump and move laterally.  more » « less
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Hilton Head Workshop 2022: A Solid-State Sensors, Actuators and Microsystems Workshop
Medium: X
Sponsoring Org:
National Science Foundation
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