Smart Materials and Systems Seminar Series
Department of Engineering Science and Mechanics
Self sufficient sensor nodes can be utilized in intelligent monitoring systems for health monitoring of machinery and infrastructure. The applications require placing the sensor nodes in hard to reach places which make changing their batteries a cumbersome and expensive task. Vibrational energy harvesting devices are piezoelectric instruments which can harvest energy from the ambient vibrational energy available in the environment to power the sensor nodes. A key challenge in developing vibrational energy harvesting devices in MEMS scales is to make them resonate at lowfrequency ambient vibrations. The talk discusses two novel compact geometries which can significantly reduce the natural frequencies of harvesting structures to the useful range. The vibrations of these geometries have been analytically modeled and experimentally investigated. Another issue in general vibrational energy harvesting area is the sensitivity of the devices to the excitation frequency. By making the structure nonlinear one can significantly enhance the bandwidth of the harvester. A novel nonlinear hybrid energy harvesting device is introduced which responds to low excitation frequencies, is frequency insensitive and enhances the power output by two orders of magnitude. The nonlinear vibrations of the hybrid device have been analytically and experimentally investigated.
Currently a member of ICTAS Doctoral Scholars Program and a PhD candidate in the department of Engineering Science and Mechanics at Virginia Tech M. Amin Karami is working in the Center for Intelligent Material Systems and Structures (CIMSS) with Prof. Daniel J. Inman. He earned a Master of Applied Science in mechanical engineering in 2006 from The University of British Columbia in Vancouver, BC, Canada and a B.SC. in Mechanical Engineering in 2004 from Sharif University of Technology, Tehran, Iran. His research interests include smart materials, energy harvesting, microelectromechanical systems, nonlinear vibrations, and dynamics of nonlinear systems.