A New Perspective on Energy Harvesting Nanowires: The Role of Chemistry and Structure of Nanowires

自供电电子设备的发展引起了全世界研究人员和高科技产业的极大兴趣。最近的研究表明，氧化锌纳米线可以作为能量收集模块为纳米/微米级器件供电。由于其半导体和压电特性，这些纳米线能够将机械能转换为电输出。目前，ZnO纳米线的化学成分和结构特征影响输出电信号的潜在纳米机制尚不清楚。这项研究旨在填补这一空白。ZnO线的电气和机械耦合将通过应变的纳米线使用一种新的力和电气测量系统（AFM/STM）内的透射电子显微镜（TEM）的ZnO纳米线的微观结构，可以同时监测在高分辨率进行研究。对这一现象的新认识不仅限于ZnO纳米管，还可以扩展到其他能量收集材料。拟议的研究有可能将机械运动能（如身体运动，肌肉拉伸，血压），振动能（如声波/超声波）和液压能（如血液和血管收缩等体液的流动）转换为电能。这意味着电子设备，如起搏器或笔记本电脑，可以在不需要充电的情况下通电。计划在TEM中进行为期一周的能量收集实验演示，以影响密歇根州代表性不足的少数民族和经济弱势的K-12学生。研究结果将被用作一个新的技术课程，PI已经开发，使高年级本科生和研究生从电气工程，材料科学，物理，化学和机械工程进入课堂的案例研究。还将通过万维网向社区提供显微镜实验的录像。

The development of self-powered electronic devices is of great interest to worldwide researchers and high-tech industries. Recent investigations show that zinc oxide nanowires can function as energy harvesting modules to power nano/micro-scale devices. These nanowires are able to convert the mechanical energy to electrical output due to their semiconductor and piezoelectric properties. Currently, the underlying nanoscale mechanisms by which chemical composition and structural features in ZnO nanowires affect the output electrical signal are unknown. The proposed research aims to fill this gap. The electrical and mechanical coupling of ZnO wires will be studied by straining the nanowires using a novel force and electrical measurement system (AFM/STM) inside the transmission electron microscope (TEM) where the microstructure of ZnO nanowires can be simultaneously monitored in high resolution. The new understanding on this phenomenon is not limited to ZnO nanotubes, and can be extended to other energy harvesting materials. The proposed research has the potential to convert mechanical motion energy (such as body motion, muscle stretching, blood pressure), vibration energy (such as acoustic/ultrasonic wave), and hydraulic energy (such as flow of body fluids including blood and contraction of blood vessels) into electric energy. This means that electronic devices such as pacemakers or laptops can be powered up without the need to recharge their batteries. A week-long demonstration of energy harvesting experiments in TEM has been planned to impact under-represented minority and economically-disadvantaged K-12 students in the state of Michigan. The research results will be used as a case study in a new technical course, which the PI has developed to bring senior undergraduate and graduate students from electrical engineering, materials science, physics, chemistry, and mechanical engineering into the classroom. The videos of microscopy experiments will also be made available to the community via the World Wide Web.