A microfabricated fringing field capacitive pH sensor with an integrated readout circuit

被引：10

作者：

Arefin, Md Shamsul ^{[1
]}

Coskun, M. Bulut ^{[1
]}

Alan, Tuncay ^{[1
]}

Redoute, Jean-Michel ^{[1
]}

Neild, Adrian ^{[1
]}

Yuce, Mehmet Rasit ^{[1
]}

机构：

[1] Monash Univ, Melbourne, Vic 3004, Australia

来源：

APPLIED PHYSICS LETTERS | 2014年 / 104卷 / 22期

关键词：

Natural frequencies - Readout systems - Circuit oscillations - Pelletizing - Capacitance - Silicones - Capacitive sensors - pH sensors - Microfabrication;

D O I：

10.1063/1.4881263

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

This work presents a microfabricated fringe-field capacitive pH sensor using interdigitated electrodes and an integrated modulation-based readout circuit. The changes in capacitance of the sensor result from the permittivity changes due to pH variations and are converted to frequency shifts using a crossed-coupled voltage controlled oscillator readout circuit. The shift in resonant frequency of the readout circuit is 30.96MHz for a change in pH of 1.0-5.0. The sensor can be used for the measurement of low pH levels, such as gastric acid, and can be integrated with electronic pills. The measurement results show high repeatability, low noise, and a stable output. (C) 2014 AIP Publishing LLC.

引用

页数：4

共 22 条

[1] On the use of MOS varactors in RF VCO's [J].