High accuracy differential capacitive circuit for bioparticles sensing applications

Abstract

A linear differential capacitive circuit is presented. This circuit is based on a charge-based capacitance measurement (CBCM) technique. The proposed circuit is optimized so as to maximize the sensitivity, which is a critical parameter in capacitive sensors. The resulting sensitivity is 200mV/fF with a noise level equivalent to 5aF. This circuit is intended as an interface circuit for bioparticles detection in integrating with a microchannel which is fabricated in a new robotic based technique