Explicit topology optimization of multi-material flexoelectric composite structures for energy harvesting

The development of Micro-Electro-Mechanical Systems (MEMS) and portable electronic devices have facilitated the application of energy harvesters in self-powered microelectromechanical devices. This work presents an explicit topology optimization framework for the design of multi-material flexoelectric composite structures. It aims to achieve flexoelectric energy harvesting structures with enhanced energy conversion efficiency by optimizing the distribution of elastic and flexoelectric materials concurrently. The proposed method utilizes a set of groups of moving morphable components (MMC) to characterize the distribution of flexoelectric and elastic materials. The influence of different material overlapping schemes is also investigated in this work. The combination of isogeometric analysis (IGA) and MMC enables an efficient solution of flexoelectric high-order partial differential equations (PDEs). Numerical examples and experiments verify the effectiveness of the proposed method. Compared to other methods, the component-based MMC method not only facilitates the formation of efficient structures, but also directly produces the geometric model required for manufacturing.