Self Calibrated Readout Frontend for Capacitive Biosensors

Interfaz electrónica que compensa las variaciones de fabricación del biosensor capacitivo

Abstract

In sensors, as in any other area, the fabrication process presents variations, and in order to minimize them a new frontend architecture, that does not need a reference sensor for calibration, is presented here. The proposed system works with a DC reference signal instead of an AC signal as most of the reported works. A readout system using the proposed architecture was designed in a 180nm CMOS technology for a particular capacitive microfluidic bio-sensor to detect E.Coli bacteria. The nominal sensor has a capacitance range that goes from 192 pF to 122 pF depending on the quantity of bacteria in it, that goes from 0 to 100,000 UFC/ml respectively