IDR: Engineering Electroactive-Polymer-Based Phononic Crystals as a Sustainable Energy Source

这项跨学科研究(IDR)拨款的目的是探索一种新的分层方法，该方法将具有几何非线性的非传统晶格拓扑的设计与屈曲诱导的软化相结合，以降低工作声子频率范围，从而有效地收集能量。微型机电系统、无线传感器和电子便携设备对高效可靠的电源的需求，要求创新的机电结构和材料系统能够从低频环境机械振动中获取电能。不幸的是，材料的密度和模数成为一对相互竞争的设计约束，阻碍了低工作频率能量收集装置的实现。通过多尺度建模、设计优化、微加工和实验验证的协同方法，这项资助支持了电活性聚合物基声子晶体实现卓越的机电能量转换的大胆努力，具有同时具有能量捕获和隔振能力。如果研究成功，这项研究将通过深入了解电活性聚合物材料中声子带隙和机电耦合之间的相互作用，揭示微结构声子超材料的能量捕获机制。将基于水平集的拓扑优化扩展到多功能和多材料设计，将有助于建立一个严格的、在计算上可行的设计框架，考虑到电活性聚合物的高度非线性和机电耦合现象，同时实现制造和设计之间的双向交流。具有快速成型能力的集成微制造程序将使用全功能原型提供“硬件在环”概念验证。预计这项研究的成果将是在以科学为基础的材料力学、设计优化、光子和声子超材料以及微制造领域的多学科研究人员之间建立边界，以推动“基于声子超材料的能量收集”领域的发展，同时在跨学科学习环境中培养下一代科学和工程领导力。

The objective of this Interdisciplinary Research (IDR) grant is to explore a novel hierarchical approach that incorporates design of non-conventional lattice topologies with geometric nonlinearities and buckling-induced softening to lower the operational phononic frequency range for effective energy harvesting. The need for efficient and reliable electrical power sources for micro-electro-mechanical systems, wireless sensors and electronic portable devices, calls for innovative electromechanical structures and material systems capable of harvesting electrical energy from low frequency environmental mechanical vibrations. Unfortunately, a material's density and modulus become a pair of competing design constraints that prevent the realization of energy harvesting device with low operational frequencies. Through synergized approach among multiscale modeling, design optimization, micro-fabrication and experimental validation, this grant supports the bold effort in achieving superior electromechanical energy conversion of electroactive polymer based phononic crystals featuring simultaneous energy harvesting and vibration isolation capabilities.If successful, this research will reveal the energy harvesting mechanisms of microstructured phononic metamaterials through a deep understanding of the interplay between phononic bandgaps and the mechanical-electrical coupling in the electroactive polymer materials. The extension of level-set based topology optimization to multi-functional and multi-material design will help establishing a rigorous and computationally viable design framework accounting for the highly nonlinear and coupled mechanical-electrical phenomena of electroactive polymers, while enabling two-way communication between manufacturing and design. The integrated micro-fabrication procedure with rapid prototyping capability will offer "hardware-in-the-loop" proof of concepts using fully functional prototypes. The fruition of this research is expected to be the forging of boundaries between the multidisciplinary researchers from science-based mechanics of materials, design optimization, photonic and phononic metamaterials and micro-fabrication for advancing the field of "phononic metamaterials-based energy harvesting," while training the next generation of scientific and engineering leadership in an interdisciplinary learning environment.