Graduation Semester and Year
2019
Language
English
Document Type
Thesis
Degree Name
Master of Science in Electrical Engineering
Department
Electrical Engineering
First Advisor
Jung-Chih Chiao
Abstract
pH level of biofluid is crucial in understanding physiological health. Commercial glass electrode pH sensors are bulky and cannot provide real time data. In this study, a novel miniature pH sensor capable of continuous wireless communication was developed, which is a promising technology for providing point-of-care diagnosis. Iridium Oxide because of its wide pH sensing range and biocompatibility has attracted attention from biomedical and food industries; high sensitivity of Iridium Oxide based sensor is attributed to its high charge density. Flexible polyamide Kapton substrate (127 µm) is taken as base substrate and E-Beam method is employed to deposit adhesion and metal layers. Electrodeposition processes such as Electroplating and Sol-Gel methods are employed to deposit Iridium Oxide on the Gold (Au) film. Electroplated electrodes showed high sensitivity (Super Nernstian response) and shorter lifetime, where-as Sol-Gel electrodes showed good sensitivity (Nernstian response) with longer lifetime. Hysteresis study based on the adhesion layer showed that Chromium (Cr) based samples exhibited higher hysteresis over Copper (Cu) based samples. But a combination layer of Cu over Cr, layered under the Au film showed the best performance. This type of samples was studied to attain super Nernstian response with sensitivity of about 62mV/pH and low hysteresis among other electrode types. Further, device packaging with cost effective and method to display pH reading on digital screen using Arduino (a low power consumption tool) is also reported.
Keywords
IrOx, pH, Sol-gel, Cyclic voltammetry, Lamination
Disciplines
Electrical and Computer Engineering | Engineering
License
This work is licensed under a Creative Commons Attribution-NonCommercial-Share Alike 4.0 International License.
Recommended Citation
Chawang, Khengdauliu, "FLEXIBLE pH SENSOR FOR SMART SENSING" (2019). Electrical Engineering Theses. 375.
https://mavmatrix.uta.edu/electricaleng_theses/375
Comments
Degree granted by The University of Texas at Arlington