Acoustic Droplet-Assisted Particle Ejection through and from Agarose-Gel-Filled Petri Dish

This paper presents a novel way of ejecting particles (Polystyrene microspheres) carried by liquid droplets through and from agarose-gel-filled Petri dish with high-intensity focused-ultrasound generated from self-focusing acoustic transducers working on the 3
^rd
, 5
^th
and 9
^th
harmonic resonant frequencies of 1-mm-thick lead zirconate titanate (PZT) sheets. With different designs, the ejection spot area (related to focal size) is varied, so that the number of particles per ejection may be precisely controlled.