Sponsored By
Interdisciplinary Microsystems Group
UF Mechanical & Aerospace Engineering
UF Electrical & Computer Engineering
UF Materials Science & Engineering
Florida Semiconductor Institute
“Magnetics in MEMS: From Switched Power Converters to Wideband Adaptive RF Filters”
Friday, Sept. 5 at 2:00 pm
NVIDIA Auditorium (MALA 1000)
Abstract
The use of magnetic materials in microelectromechanical systems (MEMS)—both magnetically soft (permeable materials) and magnetically hard (permanent magnets)—opens rich new applications sets for MEMS. This presentation will discuss two such applications based on magnetic MEMS: power conversion (exploiting soft magnetics) and adaptive RF filtering in the GHz range (exploiting hard magnetics). To achieve compact switching power converters, both switching at high frequency and the use of magnetics based on high saturation flux density materials such as iron-based alloys are desirable. However, at high switching frequencies, electrically conducting magnetic materials may suffer from eddy current loss. To overcome this issue, we will discuss a materials fabrication technique that allows building up a multiscale magnetic material from a large number of insulated iron alloy sheets (lamina), at individual sheet thickness scales that suppress eddy currents (on the order of submicron to microns), and at total thicknesses (on the order of tens to hundreds of microns) that allow significant power handling. Applications in step-down power conversion for electronic systems and universal input (100-220V) chargers, as well as step-up conversion for compact powering of piezoelectric actuators, will be discussed.
In the adaptive filter application, the use of magnetics in yttrium iron garnet (YIG) spin-wave filters will be presented. YIG has an interesting property that the frequency of propagation of spin waves through this material depends on the magnitude of an externally applied static magnetic field. By varying this external magnetic field, the filter frequency can be changed without any geometric adjustment to the YIG itself. Current commercial approaches to YIG-based adaptive filters involve the use of power-intensive electromagnets to achieve the required variable field. In place of electromagnet-based bias, the use of programmable permanent magnets to create adaptive filters in the GHz range that consume zero DC power will be demonstrated.
Biography
Mark G. Allen received the B.A. degree in chemistry, the B.S.E. degree in chemical engineering, and the B.S.E. degree in electrical engineering from the University of Pennsylvania, Philadelphia, and the S.M. and Ph.D. degrees from the Massachusetts Institute of Technology, Cambridge. He joined the faculty of the School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, ultimately holding the rank of Regents’ Professor and the J.M. Pettit Professorship in Microelectronics, as well as multiple administrative positions, including Senior Vice Provost for Research and Innovation, and Director of the Institute for Electronics and Nanotechnology.
In 2013 he left Georgia Tech to become the Alfred Fitler Moore Professor of Electrical and Systems Engineering and Scientific Director of the Singh Nanotechnology Center at the University of Pennsylvania, a post he held until 2024. Currently he is Chair of the Department of Electrical and Systems Engineering at Penn. His research interests are in the development and the application of new micro- and nanofabrication technologies, as well as microelectromechanical systems (MEMS).
He has held the posts of Editor-in-Chief of the Journal of Micromechanics and Microengineering, co-chair of the IEEE MEMS Conference, co-chair of the Power MEMS Conference, chair of the Solid State Sensors, Actuators, and Microsystems Conference (‘Hilton Head’), and chair of the IEEE Power Supply on a Chip (PwrSoC) conference. He has also co-founded multiple MEMS companies, including Cardiomems, Axion Biosystems, and Enachip. He received the Institute of Electrical and Electronics Engineers (IEEE) 2016 Daniel P. Noble Award for Emerging Technologies “for contributions to research and development, clinical translation, and commercialization of
biomedical microsystems. He is a Fellow of the IEEE, a member of the National Academy of Inventors, and a member of the National Academy of Engineering.
Dr. Allen will also give a career-perspective seminar, entitled “A Journey Through MEMS: Reflections on Research, Commercialization, and Community,” Thursday, Sept. 4 at 4:00 pm, NVIDIA Auditorium.