Acoustic metamaterial-based energy harvesting of mechanical waves: Modeling, optimization and experiments

声学超材料（AMMs）是一种由小单元胞组成的人工周期结构，具有连续材料的特性，具有非常规的有效性能。声波和弹性波在人工晶体中可能表现出许多异常现象，如负折射、超透镜、隐形和局部化，因此具有许多创新和具有挑战性的工程应用。将压电结构引入到基于am的场集中器中，可以设计能量收集器，将传播波的机械能收集并转化为电能。本项目将开发基于am的机械波场集中器，并研究在场集中器中传播的声/弹性波的压电能量收集。本课题的科研目标是：利用变换声学/弹性动力学设计传播机械波（声波/弹性波）的场集中器。基于有限元法的单元格拓扑优化设计。建立了计算压电结构机电响应的解析建模和数值模拟方法。能量收集装置的多场数值模拟、装置的制造和实验室能量收集效率的测量。

Acoustic metamaterials (AMMs) are artificial periodic structures composed of small unit-cells which behave like a continuous material with unconventional effective properties. Acoustic and elastic waves in AMMs may show many anomalous phenomena, e.g. negative refraction, superlensing, cloaking and localization, and thus have many innovative and challenging engineering applications. Energy harvesters, which can collect the mechanical energy of propagating waves and convert it into electrical power, may be designed by introducing piezoelectric structures into AMM-based field concentrators. In the proposed project, AMM-based field concentrators for mechanical waves will be developed, and the piezoelectric energy harvesting of propagating acoustic/elastic waves in the field concentrators will be studied. The scientific objectives of the present research project are:  Design of the field concentrators for propagating mechanical waves (acoustic/elastic waves) by transformation acoustics/elastodynamics. Topology optimization for the unit-cell design based on the finite element method (FEM). Development of the analytical modeling and numerical simulation methods for calculating the electromechanical responses of the piezoelectric structures. Multi-field numerical simulations of the energy harvesting devices, manufacturing of the devices and measurements of the energy harvesting efficiency in the laboratory.