Nanoscale Magnets: Enabling Ultrasensitive Point-of-Care Diagnostics

Drew Hall

Assistant Professor of Electrical & Compute Engineering

University of California, San Diego


Seminar Information

Seminar Date
January 29, 2016 - 11:45 AM

Location
Fung Auditorium | Powell-Focht Bioengineering Hall

Abstract

With increases in healthcare costs, a constantly expanding population, and a limited supply of physicians, radical changes must be made for the healthcare system to remain sustainable. Consumer electronics are ubiquitous and inexpensive today, whereas most medical devices are costly and access is primarily limited to hospitals. A compelling solution to this problem is to alleviate some of the burden on the healthcare system by equipping the general population with tools to make their own diagnoses. This is especially important in developing countries around the world where trained technicians and large centralized laboratories simply do not exist. Just as miniaturization of computers, which once filled large rooms, into the microprocessor revolutionized the computer industry, miniaturization of medical diagnostic tools has the potential to restructure our healthcare system in a similar fashion. The future of basic diagnostic medicine will lie in the hands of individuals.

Giant magnetoresistive spin-valve (GMR SV) sensors coupled with magnetic nanotags (MNTs) possess great promise as ultrasensitive biosensors for diagnostics. In this talk, I will describe two platforms built using this technology. The first is an integrated sensor interface for an array of 256 GMR SV biosensors designed in 0.18 μm CMOS. Arranged like an imager, each of the 16 column level readout channels contains an analog front-end and a compact ΣΔ modulator (0.054 mm2) with 84 dB of dynamic range and an input referred noise of 49 nT/√Hz. In the second part of the talk, I will show how this system can be miniaturized for point-of-care (POC) diagnostics. This platform, which we call the nanoLAB, addresses the growing need in global health for more sensitive POC testing. We demonstrate state of the art sensitivity with 8-plex detection using a wash-free assay that can be run by anyone, anywhere. This platform was tested and validated using human immunodeficiency virus (HIV) biomarkers with detection down to 50 fM in as little as 15 minutes. Lastly, I will talk about some of our future work on a defect-tolerant design for magnetic tunnel junction (MTJ) sensors.

Speaker Bio
Dr. Hall received the B.S. degree in computer engineering with honors from the University of Nevada, Las Vegas in 2005 along with M.S. and Ph.D. degrees in electrical engineering from Stanford University in 2008 and 2012, respectively. In the past, he has held internship positions with General Electric, Bentley Nevada Corporation, and National Semiconductor Corporation where he worked on low-power, precision analog circuit design. He worked as a research scientist at the Intel Corporation from 2011 to 2013 in the integrated biosensors laboratory. In 2013, he joined the Jacobs School of Engineering at the University of California, San Diego as an assistant professor in the Department of Electrical and Computer Engineering.  His research interests include bioelectronics, biosensors, analog circuit design, medical electronics, and sensor interfaces. Dr. Hall was the recipient of the 2011 Analog Devices Outstanding Designer Award, won 1st place in both the inaugural international IEEE Change the World Competition and the BME-IDEA invention competition. He is also a Tau Beta Pi fellow.