Title
Optimizing Sensitivity of Capacitive Pressure Sensors for Improved Intraocular Pressure Monitoring: Exploring the Impact of Spiral Shaped Antenna Geometries on Q-Factor and Resonance Frequency Output
Author
Griffith, Kiana (TU Delft Mechanical, Maritime and Materials Engineering)
Contributor
Muratore, D.G. (mentor)
Boutry, C.M. (mentor)
Degree granting institution
Delft University of Technology
Programme
Biomedical Engineering
Date
2023-08-23
Abstract
This thesis analyzes and describes a wearable pressure sensor to detect intraocular pressure and guide clinician diagnosis of glaucoma. Although glaucoma has many
symptoms and risk factors, high intraocular pressure is the most predominant. A method to continuously and accurately record intraocular pressure measurements and fluctuations in a patient could lead to a more reliable glaucoma diagnosis and a better understanding of glaucoma progression. The proposed sensor consists of an ecoflex dielectric layer, between two graphene-silver nanowire spiral antenna electrodes which also act as the membrane structure. The sensor deflection depends on the intraocular pressure fluctuations; higher pressure leads to larger deflection values, therefore, larger capacitance change. The capacitance change leads to a shift of the resonant frequency, which is simulated in this thesis. The sensor must be smaller than 11 mm2
to fit on a commercial lens. Specifically, this thesis analyzes and simulates the effects
of electrode thickness and shape on the overall performance of the sensor. The optimum geometry of the capacitive sensor is analyzed to maximize sensor sensitivity and quality factor, with a correlated frequency appropriate for a wearable lens. Using Computer Simulation Technology, the optimized antenna dimensions are spiral-electrodes with a plate thickness of 350µm, and 3 spiral revolutions; leading to an increase in sensitivity of 1.4 MHz/mmHg.
Subject
Intraocular pressure
Wearable Contact Lens Sensor
Spiral antenna
To reference this document use:
http://resolver.tudelft.nl/uuid:3a7b0669-73aa-4aea-b01d-ca00401e3433
Embargo date
2025-08-23
Part of collection
Student theses
Document type
master thesis
Rights
© 2023 Kiana Griffith