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

自供电电子器件的发展引起了世界各国研究人员和高技术产业的极大兴趣。最近的研究表明，氧化锌纳米线可以作为能量收集模块来驱动纳米/微米级的器件。这些纳米线由于其半导体和压电性能，能够将机械能转换为电力输出。目前，氧化锌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级机制尚不清楚。这项拟议的研究旨在填补这一空白。利用一种新型的力和电测量系统(AFM/STM)在透射电子显微镜内同时高分辨率地监测氧化锌纳米线的微结构，研究了氧化锌纳米线的电学和机械耦合。对这一现象的新认识并不局限于氧化锌纳米管，还可以推广到其他能量收集材料。这项拟议的研究有可能将机械运动能量(如身体运动、肌肉伸展、血压)、振动能量(如声波/超声波)和水力能量(如体液流动和血管收缩)转化为电能。这意味着，起搏器或笔记本电脑等电子设备无需充电即可通电。密歇根州计划进行为期一周的能量收集实验演示，以影响代表不足的少数族裔和经济困难的K-12学生。研究成果将被用作一门新的技术课程的案例研究，该课程是PI开发的，旨在将电气工程、材料科学、物理、化学和机械工程的高年级本科生和研究生带入课堂。显微镜实验的视频也将通过万维网提供给社区。

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.