Vibration energy is abundant in nature such as human motions, industry machines, and automobiles and is a viable choice to power wireless sensor nodes. The most popular transducers for vibration energy harvesting are piezoelectric (PZT) (lead, zicronate, and titanate) cantilevers, which offer high energy density, good scalability, and various shapes. The power conditioning circuit for a piezoelectric generator needs a maximum power point tracking (MPPT) to maximize the power transfer, while minimizing power consumption of the circuit. We implemented an MPPT algorithm with a low-power microcontroller unit (MCU) and with a mixed-signal IC in 0.18 um CMOS technology, and both methods intend to match the source resistance dynamically. We also investigated vibration energy harvesting for wide bandwidth. The presentation focuses on our research endeavors for power management circuits for vibration energy harvesting.
Dong Ha received a B.S. degree in electrical engineering from Seoul National University, Korea, and M.S. and Ph.D. degrees in electrical and computer engineering from the University of Iowa, in 1984 and 1986, respectively. Since Fall 1986, he has been a faculty member of the Department of Electrical and Computer Engineering, Virginia Tech. Currently, he is Professor and Director of Multifunctional Integrated Circuits and Systems (MICS) group. He is also a member of Center for Energy Harvesting Materials and Systems (CEHMS) of Virginia Tech and University of Texas at Dallas. His group conducts research in power management circuits for energy harvesting, wireless motion sensors, a transceiver for high speed fiber optic communications, and high temperature RF ICs. He is a Fellow of the IEEE.