Graduation Semester and Year
Spring 2024
Language
English
Document Type
Dissertation
Degree Name
Doctor of Philosophy in Electrical Engineering
Department
Electrical Engineering
First Advisor
Sungyong Jung
Abstract
Electrochemical sensing systems have emerged as indispensable tools in various fields due to their remarkable sensitivity, selectivity, and versatility. They play a pivotal role in modern research, industry, environmental monitoring, and healthcare devices. In environmental monitoring, these systems are deployed for detecting pollutants, heavy metals, and toxic gases, facilitating real-time monitoring, and ensuring environmental safety. Whereas, in the biomedical field, electrochemical sensing systems play a crucial role in diagnosing diseases, monitoring biomarkers etc, thereby revolutionizing healthcare practices.
Cost-effective wearable electrochemical sensing devices are significant for democratizing healthcare and improving public health outcomes. These devices enable continuous monitoring of physiological parameters, facilitating early disease detection, personalized medicine, and remote patient monitoring. By providing affordable tools for health tracking and data collection, they empower individuals to take proactive steps towards managing their health and well-being. Furthermore, recent advancements in electrochemical sensing technology, including the integration of nanomaterials have led to the development of high-density sensor arrays. These innovations resulted in enhanced sensitivity, miniaturization, and portability, opening up new avenues for point-of-care diagnostics, personalized medicine, and remote monitoring.
This work highlights the significance of electrochemical sensing systems, elucidating their applications in biomedical and environmental fields by the development of various wearable electrochemical sensing systems such as Indoor air quality measurement system, Watch-type triple-mode healthcare device, and Wearable diabetes monitoring device. Advancing to high-density sensor arrays, a wearable and high-speed readout circuit is developed on a printed circuit board (PCB) for precise measurement of wide range chemiresistive sensors. The proposed readout circuit on PCB for chemiresistive sensors can measure a wide range of 1KΩ to 1MΩ. The wearable version PCB supports 60 sensor measurement with an error rate of 2.5%, measurement speed of 19.6ms/sensor and occupies 3 x 3cm. Whereas, the high-speed version PCB supports a higher density array with 118 sensors and has an error rate of 0.88%, measurement speed of 8.5ms/sensor and occupies 10 x 6cm.
Furthermore, to reduce size and power consumption for wearable devices, an impedimetric readout circuit is designed in CMOS integrated circuit (IC). Impedimetric readout circuits are essential as they precisely measure changes in impedance and help to characterize new sensors. The proposed impedimetric readout circuit designed in 0.18µm CMOS IC can accommodate an input current range of 10nA to 1mA, consumes a power of 7.19mA and occupies an area of 400 x 1860µm2
Keywords
Wearable sensing system, High density sensor array, Electrochemical sensing, Impedimetric readout
Disciplines
VLSI and Circuits, Embedded and Hardware Systems
License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License
Recommended Citation
Lakshminarayana, Shanthala, "A Wearable Sensing System for High-Speed Interface of Wide Range Electrochemical Sensor Array" (2024). Electrical Engineering Dissertations. 3.
https://mavmatrix.uta.edu/electricaleng_dissertations/3