Field-programmable acoustic array for patterning micro-objects

A field-programmable acoustic platform is introduced to enable re-configurable patterning of micro-objects into complex and non-periodic shapes with sub-wavelength resolution. Conventional acoustic methodologies are difficult in realizing versatile adjustments of potential energy profiles due to the constraint of the device structure. To tackle such a challenge, we present a digitally programmable, near-field acoustic platform that permits the generation of versatile potential profiles. This platform uses an array of aqueous-medium filled cavities that can be selectively vaporized by a laser beam to pattern the acoustic wavefront of a plane wave to shape acoustic potential profiles. We have demonstrated a field-programmable acoustic platform with a digital pixel resolution of 40 mu m pitch. With a 17 mW, 532nm laser, an air cavity can be generated at a rate of 1 cavity/s.