ECE Seminar - Portable NMR/MRI with customized silicon chips
Magnetic resonance is celebrated for its capability to non-invasively probe the molecular information from the sample. Its applications range from chemical structure identification to probing protein dynamics, underground logging, and medical imaging. However, there are two major obstacles to disseminating nuclear magnetic resonance (NMR)/magnetic resonance imaging (MRI) devices outside the laboratories – size and price. Typical NMR and MRI devices require superconducting magnets and discrete electronics, which constrain the minimum size and cost of the devices. Portable NMR combining a permanent magnet and a silicon integrated circuit (IC) has recently emerged to offer the long-desired online, on-demand, or in situ NMR analysis. In this talk, I will showcase two of our recent implementations of portable NMR/MRI devices using customized silicon ICs. In the first prototype, we equip multiple NMR coils within the magnet to perform the NMR in a time-interleaving manner, going beyond the traditional single-sample-per-magnet paradigm and expediting the experimental time. In the second prototype, we pioneer the first 3-D-MRI scanner empowered by a high-voltage silicon-on-insulator IC. With a 0.52-T permanent magnet and integrating the electronics onto a 6-mm2 silicon chip, the scanner weighs 42 kg and provides a field of view (FOV) of 10 × 8 × 8 mm3. The key functionality of the 3-D-MRI scanner is exhibited with two fruit samples: raspberry and pomegranate, achieving a resolution of 110 × 117 × 250 μm3, in 0.17 min.
Ka-Meng Lei received the B.Sc. degree in Electrical and Electronic Engineering from the University of Macau in 2012, and the Ph.D. degree in Electrical and Computer Engineering from the same University in 2016. He has served as an Assistant professor at the University of Macau since 2019. He was a Postdoctoral Fellow at Harvard University from 2017 to 2019, where he was involved in developing the high-resolution portable nuclear magnetic resonance (NMR) spectrometer.
Ka-Meng Lei has published 40+ referred papers. He co-authored one book Handheld Total Chemical and Biological Analysis Systems: Bridging NMR, Digital Microfluidics, and Semiconductors (Springer’18) and book chapters Micro-NMR on CMOS for Biomolecular Sensing (Springer’18) and Ultra-Low-Voltage Clock References (Springer’23). His research interests include ultra-low voltage analog circuit techniques, sensors and analog front-end interfaces, and high-resolution portable NMR/Magnetic Resonance Imaging platforms.
He was a (co-)recipient of the Chipidea Microelectronics Prize 2017 (postgraduate), Best Paper Award in ASQED 2013, the Distinguished Design Award from the IEEE A-SSCC 2015, the Silkroad Award from the ISSCC 2016, the FDCT Macao Science and Technology Award for Postgraduates 2016, the 2016 Young Researcher Award from the Instituto International de Macau, and the IEEE SSCS Predoctoral Achievement Award in 2017. Dr. Lei was on the organizing committee of the IEEE Asian Solid-State Circuits Conference 2019. He is the TPC member of the ICTA 2021 - 2023. Dr. Lei is the AE of the IEEE Open Journal of Circuits and Systems. He now serves as the IEEE SSCS Young Professionals committee member, coordinating the Webinars for Young Excellence program.