Compound Readout Circuit Applied for Electronic Tongue

• Main Authors: Jun-Bin Chen, 陳俊賓
• Other Authors: Wen-Yaw Chung
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/55618990297370109362

碩士 === 中原大學 === 電子工程研究所 === 99 === Currently biomedical research developed towards the application of electronic tongue, and electronic tongue primary to replace human taste. Its advantage is that you can quickly analyze the composition of the liquid solution. According to the different chemical substances, it can be divided into molecular sensing and ion sensing. The electronic tongue system consists of electrochemical sensors for front-end signal readout devices. Based on the different transmission mechanism, ion sensing (hydrogen ion, chloride ion, sodium ion) is potentiometric, and molecular sensing (glucose, carbamide) is amperometric. This thesis proposes a compound readout circuit applied for electronic tongue, it integrates the readout circuit of potentiometric and amperometric. It enhances the efficiency of analog to digital converter through level shift circuit, digital to analog converter and programmable gain amplifier. Currently it used in the detection of hydrogen ion and glucose. The chip measurements of compound readout circuit show that the sensitivity and linearity of potentiometric are 50.538mV/pH and 99.9565% respectively. The sensitivity and linearity of amperometric are 18.635mV/uA and 99.9918% respectively. Analog to digital converter performs well in linear conversion, and the linearity is up to 99.5437%.