a 1620 electrochemical cmos biosensor array with in-pixel averaging using polar modulation

Department: Electrical & Computer Engineering
Faculty Advisor(s): Drew A. Hall

Primary Student
Name: Alexander Chuan Sun
Email: acs009@ucsd.edu
Phone: 650-393-3939
Grad Year: 2018

Biosensors based on electrochemical impedance spectroscopy (EIS), an ultra-sensitive, label-free sensing technique, are a promising technology for precise and rapid disease diagnosis at the point-of-care (POC). However, EIS usually requires mixers and lock-in detection to measure both the magnitude and phase of the complex impedance. To address this issue, we report a 1620 electrochemical biosensor array with on-chip sensors that implements a polar-mode measurement method that allows the readout circuitry to be mostly digital and small enough to fit within a 140140 m2 pixel. The architecture enables in-pixel digitization and accumulation, which increases the SNR by 10 dB for each 10 increase in readout time. Implemented in a 0.18 m process, the 34 mm2 chip achieves state-of-the-art performance with an rms phase error of 0.04% at 50 kHz and was used to measure hybridization of Zika virus oligonucleotides.

Industry Application Area(s)
Electronics/Photonics | Life Sciences/Medical Devices & Instruments

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