Acoustic waves play an important role in many applications, such as homeland security (e.g. sonar systems), healthcare (e.g. ultrasound imaging), and industry (e.g., non-destructive damage detections). However, there are currently limited functional acoustic materials that can effectively control and manipulate acoustic waves and be employed for next-generation acoustic-based devices. This award supports fundamental research on guiding, compression, amplification, and localization of acoustic waves through novel artificial acoustic materials (i.e., acoustic metamaterials). These engineered materials possess unique properties that are unachievable in natural materials. This work will open up new avenues towards the development of novel functional acoustic devices, which can potentially overcome the fundamental limitations encountered in conventional acoustic technologies. Various disciplines including physics, material science, medicine, measurement science, and energy sciences will benefit from different facets of this research. This award will also help broaden the participation of underrepresented groups in research and enrich the learning experience of students with innovative projects in an interdisciplinary curriculum integrated with the research findings.
Through combined analytical, numerical, and experimental studies, the goal of this work is to achieve a fundamental understanding of the acoustic wave propagation and guiding mechanisms, material dispersion, effective refractive indices in various graded-index metamaterial waveguides. The largely unexplored properties of these acoustic metamaterials, including the remarkable wave compression and field amplification properties, will be investigated. This research will enrich the knowledge in the growing field of anisotropic metamaterials and lead to new methodologies for control and manipulation of acoustic fields with metamaterials. Furthermore, a novel experimental approach based on a fiber optic acoustic scanning system with graphene based fiber optic probes will be developed, which will offer an entirely new way for mapping and visualization of wave propagation properties in acoustic metamaterials. In addition, this award can also lead to the discovery of fundamentally new physical phenomena in graded-index metamaterial waveguides arrays (bulk graded index metamaterials) in terms of energy coupling, scattering, and localization.
