Capacitive micromachined ultrasonic transducers for acoustic manipulation

This paper presents for the first time the single-beam acoustic manipulation of micro-particles using capacitive micromachined ultrasonic transducers (cMUTs). We demonstrate polydimethylsiloxane (PDMS) micro-particles trapping in water using a 1.8 MHz hexagonal cMUT annular array as test vehicle. FEM simulations show that PDMS particles can be trapped on the center axis of a single cMUT cell relying solely on natural focusing. Experimental results confirm these findings. To our best knowledge, it is the first time to realize a single-beam acoustic trapping of micro-particles using three-dimensional confinement. Besides, it establishes cMUTs as good candidates for acoustic manipulation offering large potential for highly miniaturized and complex acoustic tweezers.