Hyusim Park

Graduation Semester and Year

2021

Language

English

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Electrical Engineering

Department

Electrical Engineering

First Advisor

Sungyong Jung

Abstract

The sensitive and cost-effective electrochemical sensors based on various classes of nanocomposites fabricated by different methods for the detection of target chemicals. Its application is boundless from reactive monitoring of food additives, human health to environmental safety. In proportion to electrochemical sensor’s usages, the researchers’ interests in electrochemical sensing system have been grown, especially in portable system to satisfy many of the requirements for on-site and in-situ measurements. The electrochemical sensing system is consisted of sensor and electric readout circuit. The one of the most efficient way to carry out the reading of a set of electrochemical sensors for portable system is to organize them in an array form. This reduces the number of interconnections of the sensors significantly. To compose the array form, the sharing columns and lows, also called as 2-D networked array, is generally adopted. The drawback in this architecture is the appearance of crosstalk (the influence of the resistance of unscanned sensors on the measurements) which makes electrochemical readout circuit challengeable. Although different proposals have been presented in the literature to reduce this crosstalk current, errors in determining the resistance values of each sensor still exist in previous the proposals. In this work, precise and compact electrochemical readout for high-density 2-D networked chemiresistor sensor array with wide range is presented on PCB. Furthermore, to reduce size more and cover wider range of the electrochemical sensor, electric readout circuit is designed in CMOS integrated circuit (IC). Proposed electric readout for electrochemical sensing system on PCB can measure the high-density 2-D networked chemiresistor array ranged in 100K to 1M with less than 2% error rate. The proposed architecture implemented on the PCB consumes 57.30 X 37.10 mm^2 which is suitable as the portable system. Circuit presented in IC design occupies 1030 X 620 um^2 and can accommodate the chemiresistor ranged in 10K to 2M with less than 1% error rate.

Keywords

Electrochemical sensing system

Disciplines

Electrical and Computer Engineering | Engineering

Comments

Degree granted by The University of Texas at Arlington

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