Large area Waveguide Energy Harvesting Based on Fully Polarized Elastic Topological Metamaterials

Abstract

To address the challenge that elastic wave energy can only transmit through narrow path waveguides in topological metamaterials, the proposal of large area waveguides effectively breaks through this technical bottleneck. Nevertheless, elastic waves are vector waves with complex multi component transmission characteristics. Realizing the cooperative transmission of in plane and out of plane fully polarized components poses substantial challenges for elastic wave energy transmission and trapping applications. To tackle the above mentioned problems, this paper proposes a fully polarized elastic topological heterostructure based on the quantum valley Hall effect. First, symmetric unit cell structures are designed to obtain unit cells with distinct topological properties for in plane and out of plane modes, and multiple types of supercell structures are fabricated to realize the simultaneous transmission of fully polarized elastic wave energy for both in plane and out of plane components. Furthermore, a gradient valley locked structure is designed using large area waveguide states to constrain and converge the transmitted energy, and its energy harvesting performance is analyzed. The results demonstrate that the proposed structure enables coupled transmission of fully polarized elastic wave components. Moreover, the energy harvesting capability of the gradient valley locked phononic crystal plate is approximately 4.79 times that of conventional single component transmission structures, which greatly improves the efficiency and transmission stability of acoustic energy harvesting. This work provides new insights for the engineering application of topological metamaterials in the field of energy harvesting.