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.

小型传感器 - 在微观或纳米级 - 有望将人类的看法扩展到极端和以前难以接近的环境。这些下一代独立传感器系统将如何供电？许多现有解决方案使用压电材料将机械振动转化为电力。但是，只有一小类材料实际上表现出这种形式的机电耦合的水平，并且通常在较高温度下失去压电。这排除了它们在最需要新的传感器类别的环境中的使用。此外，性能最高的压电材料含有铅，从而产生制造和处置危害。该项目通过一种完全不同的现象调查了发电，称为Flexoelectricity。与压电性不同，在所有介电固体中都存在柔韧性，因此提供了一种具有环境兼容的压电替代品。该项目结合了互补的计算研究和实验研究，以探索和理解从原子量表到设备级别的挠性性。这项工作将为能源收集设备的性能大大增强提供一个新颖的框架。该协作研究计划结合了原子和连续的电弹性建模，非线性动态现象，纳米化，多尺度实验和设备表征，以促进在小规模上建立一类新型的革命性自动传感器和传感系统。通过使用严格的实验桥接原子和连续理论，将建立一个完全耦合的挠性能量收割机框架，以探索用于转换效率和功率密度的缩放定律。对于高激发水平，也将表征非线性弹性，电弹性和耗散效应。基于这种从根本上进行机电能量收集的变革性方法，挠性电性和基于连续的能量收集模型的原子建模将与实验结合起来，以建立下一代能量收获者。将探索线性和非线性宽带体系结构，以收集确定性和随机振动能。这项研究还将建立一个框架和彻底理解纳米结构的电弹性动力学，以用于在亚微米尺度上涉及涉及双向机电耦合（例如传感，驱动，控制）的各种其他问题。