An All-Polarized Elastic Topological Metamaterial for Ultrasonic Energy Conveying and Harvesting

Microelastic topological metamaterials (METMs) are of great use in the robust conveying and harvesting of high-frequency ultrasonic energies. However, current METMs only hold topological edge states of a single flexural mode, restricting their capacity to convey ultrasonic energies of other polarized elastic waves. Moreover, the potential of METMs for ultrasonic energy harvesting remains unexplored. To address these challenges, an all-polarized elastic topological metamaterial (AETM) is developed, capable of simultaneous conveying and harvesting of ultrasonic energies from elastic waves of all polarizations. This AETM supports broadband topological edge states for both out-of-plane and in-plane modes, enabling the robust conveying of ultrasonic energies from all-polarized elastic waves. Subsequently, by integrating the AETM with a piezoelectric energy harvester, efficient harvesting of ultrasonic energies conveyed by the AETM is achieved. Notably, the developed AETM with structural simplicity can be easily integrated into micro-electromechanical systems (MEMSs) for on-chip ultrasonic wave communication and energy harvesting. This work advances the development of topological metamaterials that can concurrently convey and harvest ultrasonic energies from all-polarized elastic waves, offering significant potential for various MEMS applications.