MEMS First-Order Bessel Beam Acoustic Transducer for Particle Trapping And Controllable Rotating

This paper reports a novel and easy-to-fabricate MEMS first-order Bessel beam acoustic transducer (BBAT) for particle trapping and electrically controllable rotating, in terms of the design, fabrication, characterization, and experiments. The BBAT is primarily composed of a bulk lead zirconate titanate (PZT) ceramic and polydimethylsiloxane (PDMS) membrane, bonded by SU-8 photoresist. The transducer encloses customized air-cavities in order to generate Archimedes’ spiral acoustic source. We prototyped a 2.32 MHz BBAT with the design, which was capable of firmly trapping polystyrene (PS) particles as large as 800 μm diameter under 18 V
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, and precisely steering the rotating velocity by controlling the driving voltage. A linear relationship between the rotating velocity and driving volage square was observed, which can reach as high as 138 rpm under 150 V
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.