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: 1463339
• 负责人: Alper Erturk
• 金额: $ 37.78万
• 依托单位: Georgia Tech Research Corporation
• 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=1463339&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能力扩展到极端和以前无法进入的环境。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化为电能。然而，只有一小类材料表现出实际有用的这种形式的机电耦合水平，而这些材料通常在较高的温度下失去其压电性。这使得它们无法在最需要新型传感器的环境中使用。此外，性能最高的压电材料含有铅，这会造成制造和处置危害。这个项目通过一种完全不同的现象来研究发电，叫做柔性发电。与压电不同，柔性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方案。该项目结合了互补的计算和实验研究，从原子尺度到设备层面探索和理解柔性电。这项工作将为能量收集装置的性能显著提高提供一个新的框架。这个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、纳米制造、多尺度实验和设备表征，以促进在小尺度上建立一种新型的革命性自供电传感器和传感系统。通过将原子理论和连续介质理论与严谨的实验相结合，建立了一个全耦合柔性电能量采集器框架，以探索转换效率和功率密度的标度规律。对于高激励水平，非线性弹性，电弹性和耗散效应的柔性电能收集也将被表征。基于这种机电能量收集的根本性变革方法，柔性电力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。线性和非线性的宽带架构将被探索用于收集确定性和随机振动能量。这项研究还将建立一个框架，并全面了解纳米结构的电弹性动力学，用于亚微米尺度上涉及双向机电耦合（例如传感、驱动、控制）的各种其他问题。