CAREER: Understanding the Fundamental Dynamics of Angular Momentum Carrying Acoustic Wave Propagation

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

This Faculty Early Career Development (CAREER) grant will enable the development of new knowledge related to the propagation of angular momentum carrying acoustic waves in anisotropic biomaterials, which is critical for their use in biomedical imaging, therapies, and treatment. Angular momentum carrying acoustic waves, such as acoustic vortex beam, are a special type of sound waves that have a rotating pressure field or energy flux. Previous studies indicated that these waves could have many potential biomedical applications, including medical imaging with better resolution than traditional ultrasound imaging and targeted ultrasonic removal of kidney stones and blood clots with higher efficacy than classical focused ultrasound therapies. However, these studies focused on waves propagating underwater and ignored the anisotropy and heterogeneity of biomaterials such as muscle fibers. Recent theoretical studies have indicated that acoustic angular momenta will couple when propagating in anisotropic or heterogeneity materials, altering the propagation path of the wave, and potentially impeding their reliable use in the suggested biomedical applications. The research supported by this CAREER award seeks to understand the fundamental coupling mechanism between different acoustic angular momenta, especially when propagating in anisotropic biomaterials, through modeling and experimentation. This understanding will be applied to demonstrate imaging and blood clot thrombolysis capabilities through anisotropic media. The results from this research will advance knowledge in acoustics, dynamics, biomechanics, as well as biomedical engineering, and can potentially lead to novel medical diagnostics and therapies. This award will positively impact STEM education through collaboration with existing programs at Georgia Tech aimed to engage students and high school science teachers from the Atlanta Public Schools and Atlanta International School, especially from currently underrepresented groups, and to promote their participation in research. This award will leverage the Georgia Tech InVenture Challenge to motivate undergraduate students and encourage them to compete in this interdisciplinary innovation competition using knowledge learned from this research. The objective of this research is to create and experimentally validate new models that accurately predict the propagation of angular momentum carrying acoustic waves in anisotropic media. Intrinstic and extrinsic acoustic waves become coupled when propagating in anisotropic materials, thus shifting the wave propagation trajectory. The central hypothesis of this research is that this coupling occurs through Coriolis effects resulting from rotations induced by the wave-medium interactions. The researchers will test this hypothesis in theoretical models and in experiments conducted underwater and in soft anisotropic media. They will probe the ability to translate this understanding to the suggested imaging and thrombolysis capabilities experimentally using anisotropic tissue mimicking gels. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.