Concurrent topology optimization of piezoelectric composite structures for high performance energy harvesting

Piezoelectric energy harvesting is vital for powering microelectronic systems, with great potential for dual-scale structures. However, implementing such designs presents challenges, such as multiphysics coupling, performance measurement, and design complexity. A concurrent topology optimization (TO) method was proposed herein. This method maximized the energy output by optimizing the macrostructure, periodic microstructure, and polarization direction. An objective function was defined as a weighted function of mechanical energy and electrical energy. In addition, a concurrent TO framework was developed based on the penalized polarized piezoelectric material (PEMAP-P) model by incorporating both macro and micro density design variables as well as polarization direction design variables. This framework optimized the sum of mechanical energy and electrical energy, thereby improving the energy harvesting performance. An explicit sensitivity analysis relative to macro and micro design variables as well as the polarization direction design variables was derived. The optimization problem was solved using mathematical programming algorithms. Additionally, numerical simulations corroborate the effectiveness of the proposed design, demonstrating enhanced energy-harvesting performance with minimal loss of structural stiffness. The optimized design also exhibited excellent static and dynamic properties in finite element simulations, offering valuable insights into the design of microelectronic structures and self-powered devices.