Acoustic Droplet Vaporization

Acoustic droplet vaporization is the vaporization of micron-sized droplets by ultrasound. Our collaborator Prof. Oliver D. Kripfgans from U. of Michigan's Department of Radiology is investigating how to use this mechanism for a localized drug-delivery method for chemotherapy. The proposed therapy would begin by injecting an emulsion of drug-laden droplets into a cancerous tissue via an IV administration. The droplets will remain neutral to the surrounding tissue until ultrasound is focused on the targeted tissue and cause the the droplets to vaporize. Once the droplets vaporize into a bubble, the embedded chemotherapeutic drug can readily diffuses into the nearby cancerous tissue. The physical mechanism behind acoustic droplet vaporization has been poorly understood until recent developments in the field. In collaboration with Prof. Oliver D. Kripfgans and my advisor Prof. Charles Doering, we have made progress towards this problem by developing a theoretical model of the hydrodynamic interaction between the ultrasound and droplet to determine the induced pressures present within the droplet [1]. Then, by applying classical nucleation theory, we were able to predict which ultrasonic waveforms trigger acoustic droplet vaporization. In addition, we conducted experiments for verification of the model.

[1] C. J. Miles, C. R. Doering, O. D. Kripfgans, Nucleation pressure threshold in acoustic droplet vaporization, Journal of Applied Physics 120, 034903 (2016)