Droplets in Acoustic Fields: A Unified Theory from Migration to Splitting

We present a comprehensive theoretical framework governing the dynamics of droplets in acoustic fields, applicable to all droplet sizes, from the Rayleigh limit (D<<lambda) and beyond. Our theory elucidates the nature of acoustic forces and incorporates the effects of interfacial tension, enabling predictions of droplet migration, deformation, and splitting under suitable conditions. Importantly, we demonstrate droplet deformation and splitting through bulk acoustic wave (BAW) silicon-glass microscale experiments, which validate the proposed theory.