ANN ARBOR, MI
In a breakthrough that merges mechanics and magnetism, Dr. Taehwa Lee and his team have developed a novel elastic metamaterial capable of supporting spin angular momentum (SAM) in sound waves. Published in Advanced Physics Research, the study reveals a discrete mechanical system that enables unique control of elastic waves—an achievement with exciting implications for nonreciprocal sound transport and vibration control.
The system consists of a 2D lattice made from cantilevers tipped with repulsive magnets. As vibrations travel through the structure, coupling between longitudinal and transverse motions induces rotation in the wave’s displacement field—a mechanical analog of spin. This spin-like behavior, known as elastic SAM, allows the material to exhibit features like unidirectional wave propagation and negative group velocity, both of which are typically challenging to realize in classical mechanical systems.
What sets this work apart is not only the realization of spin-carrying elastic waves, but also the ability to use spin variations to detect defects within the lattice itself. This fusion of wave control, defect detection, and magnetically tuned interactions marks a significant step toward next-generation phononic devices. Lee’s team demonstrates that structured mechanical systems can serve as platforms for manipulating wave-based information in ways once limited to optical or quantum domains.
For detailed information, please refer to the published paper in Advanced Physics Research
