Division of Biomedical Engineering

We conduct fundamental research in microscale acoustofluidics and translate the resulting physical insights into biomedical applications and mechanobiology. Our research is primarily experimental, but whenever possible it is complemented by theoretical or numerical analyses.

From a fundamental perspective, we investigate nonlinear acoustic phenomena in fluids, particularly acoustic streaming, which plays an essential role in the manipulation of particles below critical sizes. In collaboration with theoreticians at Technical University of Denmark, we discovered streaming suppression in inhomogeneous fluids and identified thermoacoustic streaming induced by temperature-gradient-induced inhomogeneities in acoustic fields.

With the goal of translating acoustofluidic technologies into clinical settings, we develop efficient acoustofluidic devices capable of generating strong acoustic fields within microchannels without requiring high input power. We pursue this goal through several strategies, including optimized actuation schemes, symmetry breaking, transducer design in collaboration with The University of Tokyo, and careful selection of piezoelectric materials. We have established an integrated characterization-optimization-fabrication design framework, which has been successfully applied to the development of polymer acoustofluidic devices.

We are also committed to improving the environmental sustainability of acoustofluidic technologies by replacing lead zirconate titanate (PZT) in bulk-wave-acoustofluidic devices with lead-free piezoelectric transducers. By identifying suitable commercially available lead-free materials, we demonstrated that devices driven by lead-free transducers can achieve performance comparable to that of PZT-driven devices at low power level, and even outperform them at intermediate to high power levels.

Our main application areas are in high-throughput nanoparticle manipulation, including the separation of extracellular vesicles and bacteria from complex sample media. These application-focused advances are grounded in our fundamental discoveries in both device engineering and nonlinear acoustic physics. We are also expanding our research into mechanobiology, where we use acoustofluidic technologies to probe the acoustic properties of cells.