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

这项跨学科研究（IDR）资助的目的是探索一种新的分层方法，该方法将非传统晶格拓扑结构的设计与几何非线性和屈曲诱导软化相结合，以降低有效能量收集的操作声子频率范围。 微机电系统、无线传感器和电子便携式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收集电能。不幸的是，材料的密度和模量成为一对相互竞争的设计约束，这阻止了具有低操作频率的能量收集装置的实现。 通过多尺度建模、设计优化、微制造和实验验证之间的协同方法，该资助支持在实现基于电活性聚合物的声子晶体的上级机电能量转换方面的大胆努力，该声子晶体具有同时的能量收集和振动隔离能力。如果成功，本研究将通过对声子带隙之间相互作用的深入理解，揭示微结构声子超材料的能量收集机制以及电活性聚合物材料中的机电耦合。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和计算可行的设计框架，解释电活性聚合物的高度非线性和耦合的机电现象，同时实现制造和设计之间的双向通信。具有快速原型制作能力的集成微制造程序将使用全功能原型提供“硬件在环”概念证明。这项研究的成果预计将是多学科研究人员之间的边界锻造，从基于科学的材料力学，设计优化，光子和声子超材料和微制造，以推进“基于声子超材料的能量收集”领域，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.