Piezoelectric Devices for Energy Efficient Electronics

by

Dr. Mary Beth Galanko,
Electronics Engineer,
U.S. Army Combat Capabilities Development Command
Army Research Laboratory

Abstract:  Piezoelectric micromechanical devices can enable novel, highly energy-efficient electronics for on- soldier and IoT applications. As new capabilities emerge in soldier-portable and sensor electronics, energy demand is expected to outpace supply. The Microsystems Power Team at the U.S. Army Combat Capabilities Command – Army Research Laboratory (ARL) has several efforts to close this gap via supply-side power transfer solutions and demand-side power reduction. This talk will highlight the team’s work, particularly focusing on piezoelectric resonators and transformers for energy efficient radios. Traditional radios exhibit a trade-off between sensitivity and power consumption, limiting their use in long-lived IoT applications. Piezoelectric MEMS resonators and transformers offer frequency selection and passive voltage amplification, which directly enhances radio frequency (RF) communications sensitivity, while consuming zero supply power. Through examination of various resonator materials and architectures, these studies have shown the need to maximize resonator figure of merit (keff2 × quality factor) and minimize piezoelectric loss tangent. These concerns pushed material choice from lead zirconate titanate (PZT) to quartz. Devices in a custom commercial quartz process have demonstrated voltage gain up to >100× at 50 MHz and ~60 fF load, the highest reported gain in a micromechanical device at these specs to the authors’ knowledge.

Speaker bio: Dr. Mary Beth Galanko is an Electronics Engineer in the Energy Conversion Branch at the U.S. Army Combat Capabilities Development Command (DEVCOM) Army Research Laboratory (ARL). Dr. Galanko earned a B.S. in Electrical and Computer Engineering with a minor in Biomedical Engineering from Cornell University in 2013. She earned the M.S. and Ph.D. degrees in Electrical and Computer Engineering from Carnegie Mellon University in 2016 and 2018, respectively. Her dissertation work focused on nonlinear microelectromechanical (MEMS) resonators for use in ultra-low-power radios. Dr. Galanko continues to work on MEMS for energy-efficient radios at ARL, focusing on radio frequency (RF) piezoelectric devices. Prior to her current position, she was an Oak Ridge Associated Universities (ORAU) Postdoctoral Fellow at ARL. Her research interests include RF transducers, MEMS nonlinearity, sensor design, and system integration of MEMS devices. Dr. Galanko also mentors K-12 students with various interests in science, technology, engineering, and mathematics (STEM).