Collaborative Research: Generating Electricity from Deformation: Multiscale Modeling and Characterization of Flexoelectricity from Atoms to Devices

合作研究：变形发电：从原子到设备的柔性电的多尺度建模和表征

• 批准号: 1463205
• 负责人: Pradeep Sharma
• 金额: $ 15.44万
• 依托单位: University of Houston
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1463205&HistoricalAwards=false
• 关键词: Collaborative; Research; Generating; Electricity; Deformation

Small sensors -- at the micro or nanoscale -- promise to extend human perception to extreme and previously inaccessible environments. How will these next-generation stand-alone sensor systems be powered? Many existing solutions use piezoelectric materials to convert mechanical vibration into electricity. However, only a small class of materials exhibits practically useful levels of this form of electromechanical coupling, and those typically lose their piezoelectricity at higher temperatures. This precludes their use in precisely the environments where the new classes of sensors are needed most. Furthermore, the highest performing piezoelectric materials contain lead, which creates manufacturing and disposal hazards. This project investigates generation of electricity by an entirely different phenomenon, called flexoelectricity. Unlike piezoelectricity, flexoelectricity is present in all dielectric solids, and thus offers an environmentally compatible alternative to piezoelectrics. This project combines complementary computational and experimental research studies to explore and understand flexoelectricity from atomistic scales to the device level. This work will enable a novel framework for the dramatically enhanced performance of energy harvesting devices. This collaborative research program combines atomistic and continuum electroelastic modeling, nonlinear dynamic phenomena, nanofabrication, multi-scale experiments, and device characterization to facilitate the establishment of a novel class of revolutionary self-powered sensors and sensing systems at small scales. By bridging the atomistic and continuum theories with rigorous experiments, a fully coupled flexoelectric energy harvester framework will be established to explore the scaling laws for conversion efficiency and power density. For high excitation levels, nonlinear elastic, electroelastic, and dissipative effects in flexoelectric energy harvesting will also be characterized. Based on this fundamentally transformative approach to electromechanical energy harvesting, atomistic modeling of flexoelectricity and continuum-based energy harvesting models will be synergistically coupled with experiments to establish next-generation energy harvesters. Both linear and nonlinear broadband architectures will be explored for harvesting deterministic and stochastic vibrational energy. This research will also establish a framework and thorough understanding of the electroelastic dynamics of nanostructures for use in a variety of other problems involving two-way electromechanical coupling (e.g. sensing, actuation, control) at submicron scales.

微型或纳米级的小型传感器有望将人类的感知扩展到极端和以前无法到达的环境。这些下一代独立传感器系统将如何供电？许多现有的解决方案使用压电材料将机械振动转换为电能。然而，只有一小类材料表现出这种形式的机电耦合的实际有用水平，并且这些材料通常在较高温度下失去压电性。这使得它们无法在最需要新型传感器的环境中使用。此外，最高性能的压电材料含有铅，会产生制造和处置危险。该项目研究通过一种完全不同的现象（称为柔性发电）发电。与压电不同，挠曲电存在于所有介电固体中，因此提供了一种环境兼容的压电替代品。该项目结合了互补的计算和实验研究，探索和理解从原子尺度到设备级别的柔性电。这项工作将为显着增强能量收集设备的性能提供一个新颖的框架。该合作研究项目结合了原子和连续电弹性建模、非线性动态现象、纳米加工、多尺度实验和器件表征，以促进建立一类新型的革命性小规模自供电传感器和传感系统。通过将原子理论和连续理论与严格的实验结合起来，将建立一个完全耦合的柔性电能量收集器框架，以探索转换效率和功率密度的标度规律。对于高激励水平，还将表征挠曲电能量收集中的非线性弹性、电弹性和耗散效应。基于这种机电能量收集的根本性变革方法，柔性电的原子建模和基于连续体的能量收集模型将与实验协同结合，以建立下一代能量收集器。将探索线性和非线性宽带架构来收集确定性和随机振动能量。这项研究还将建立一个框架并深入了解纳米结构的电弹性动力学，以用于涉及亚微米尺度双向机电耦合（例如传感、驱动、控制）的各种其他问题。