Department of Mechanical Engineering
University of Minnesota
Development of nanotechnology and low-power electronics is leading to the transformative self-powered nanosystems that exhibit ultra-small size, supersensitivity, extraordinary multi-functionality and extremely low power consumption. One of the grand challenges for the next generation nanosystem is the controlled growth of functional nanomaterials and the development of the nanoscale energy harvester to power the system. Zinc oxide (ZnO) is a piezoelectric and semiconducting materials with wide applications in optics, optoelectronics, sensors, actuators, energy and biomedical sciences. Various ZnO nanostructures have been grown in vapor or aquatic environment. Recent results presented a general growth method of ZnO nanowire arrays with orientation control. ZnO nanowire (NW) arrays have been successfully demonstrated to convert nano-scale mechanical energy into electric energy. The operation mechanism of the electric generator relies on the unique coupling of piezoelectric and semiconducting dual properties of ZnO as well as the elegant rectifying function of the Schottky barrier formed between the metal electrode and the NW. This mechanism resulted in the DC nanogenerator driven by ultrasonic wave. Recently we achieved a new breakthrough with laterally-packaged single wire generator, which solved the transient contact issue in DC nanogenerator and produced power output from low frequency and irregular mechanical disturbance, such as finger tapping and running hamster. This presentation will introduce the fundamental principle of nanogenerator and its potential applications.
Dr. Rusen Yang is an assistant professor in the Department of Mechanical Engineering at the University of Minnesota since 2010. He obtained his M.S. and B.S. in Condensed Matter Physics from Jilin University, China. In 2007, he received his PhD degree in Materials Science and Engineering from Georgia Institute of Technology, where he continued as Post Doctoral Associate till 2010. He has done extensive research in the field of nanoscience and nanotechnology, with special interest in the growth and applications of ZnO, SnO2, Zn3P2 and other nanomaterials. His most recent work on nanogenerators based on single ZnO wires made significant contribution in the field of energy harvesting. His research work has resulted in over 60 peer-reviewed journal papers, which have been cited more than 3,700 times. Dr. Yang has been recognized with the National Science Foundation CAREER award in 2012 and he has been selected for the 2013-15 class of McKnight Land-Grant Professors.