title: Magnetic Relaxation Detector for Microbead Labels.
abstract: A compact and robust magnetic label detector for biomedical assays is implemented in 0.18-μm CMOS. Detection relies on the magnetic relaxation signature of a microbead label for improved tolerance to environmental variations and relaxed dynamic range requirement, eliminating the need for baseline calibration and reference sensors. The device includes embedded electromagnets to eliminate external magnets and reduce power dissipation. Correlated double sampling combined with offset servo loops and magnetic field modulation, suppresses the detector offset to sub-μT. Single 4.5-μm magnetic beads are detected in 16 ms with a probability of error <0.1%.
authors.affiliation: Electrical Engineering and Computer Science Department, University of California at Berkeley, Berkeley, CA 94720 USA.
authors.forename: Paul Peng
authors.initials: PP
authors.lastname: Liu
authors.affiliation: Electrical Engineering and Computer Science Department, University of California at Berkeley, Berkeley, CA 94720 USA.
authors.forename: Karl
authors.initials: K
authors.lastname: Skucha
authors.affiliation: Electrical Engineering and Computer Science Department, University of California at Berkeley, Berkeley, CA 94720 USA.
authors.forename: Yida
authors.initials: Y
authors.lastname: Duan
authors.affiliation: Electrical Engineering and Computer Science Department, University of California at Berkeley, Berkeley, CA 94720 USA.
authors.forename: Mischa
authors.initials: M
authors.lastname: Megens
authors.affiliation: Electrical Engineering and Computer Science Department, University of California at Berkeley, Berkeley, CA 94720 USA.
authors.forename: Jungkyu
authors.initials: J
authors.lastname: Kim
authors.affiliation: Electrical Engineering and Computer Science Department, University of California at Berkeley, Berkeley, CA 94720 USA.
authors.forename: Igor I
authors.initials: II
authors.lastname: Izyumin
authors.affiliation: Electrical Engineering and Computer Science Department, University of California at Berkeley, Berkeley, CA 94720 USA.
authors.forename: Simone
authors.initials: S
authors.lastname: Gambini
authors.affiliation: Electrical Engineering and Computer Science Department, University of California at Berkeley, Berkeley, CA 94720 USA.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Boser
keywords: Biosensor; CMOS; magnetic bead; magnetic relaxation