Hilliard, Elias Todd
(2011)
Fabrication and Testing of a Micro-scalable pH Sensor for Implanted Biomedical Use.
Master's Thesis, University of Pittsburgh.
(Unpublished)
Abstract
Biosensors have recently moved into the arena of implantable devices. This incredible capability,to continuously monitor physiological parameters in-situ, allows for earlier and fundamentallymore accurate measurements. As pH is one of the most important biological factors, implantabledevices to measure pH are of great interest. Unfortunately, current pH sensors exhibit signal driftand require regular recalibration. Since this is impractical for implanted devices, much work isneeded in order to extend the working life of the pH sensor. The present work implemented threetechniques for fabricating a pH sensor based on an iridium oxide sensing layer that are compatiblewith micro-fabrication techniques and implantable devices. They are the oxidation of pure iridium,reactive sputtering of iridium in an oxygen environment, and anodic electrodeposition of iridiumoxide. The response of the sensors based on these indicating layers to tests in buer solution revealeda high degree of linearity. Slopes of the response were in agreement with those found in theliterature. Life tests were performed to characterize the signal drift over 20 hours of continuoususe. The established processes for fabricating the pH sensors provide a vehicle for further investigationinto techniques for extending life, specifically, by using microfluidic devices. Preliminarytests were done to show that interruption of the electrochemical circuit slows signal drift. This canbe accomplished in microscale devices using a microfluidic switching mechanism proposed here.
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Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
| Creators | Email | Pitt Username | ORCID  |
|---|
| Hilliard, Elias Todd | eth6@pitt.edu | ETH6 | |
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| ETD Committee: |
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| Date: |
30 June 2011 |
| Date Type: |
Completion |
| Defense Date: |
19 August 2009 |
| Approval Date: |
30 June 2011 |
| Submission Date: |
26 August 2009 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
Swanson School of Engineering > Mechanical Engineering |
| Degree: |
MSME - Master of Science in Mechanical Engineering |
| Thesis Type: |
Master's Thesis |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
iridium oxide; signal drift; EWOD; microfluidics |
| Other ID: |
http://etd.library.pitt.edu/ETD/available/etd-08262009-134900/, etd-08262009-134900 |
| Date Deposited: |
10 Nov 2011 20:01 |
| Last Modified: |
15 Nov 2016 13:49 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/9265 |
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