Date of Award
Corinne Lengsfeld, Ph.D.
Aerogel, Electrochemical, Gelatin, Pressure, Sensor, Transducer
In the biomedical field the need for intra organ pressure measurement can only be facilitated by adapting existing pressure sensing technology to the specific tissues under test. The customization of these sensors has only driven up cost and the need to explore new technologies has become increasingly more important. For this dissertation, we explore the use of a new technology, particularly electrochemical pressure sensing to provide a low-cost pressure sensor to fill this need. Preliminary testing showed that electrically conductive polymers exhibited a change in voltage when pressurized if bubbles were first electrolyzed in the gel creating an aerogel, and that this effect was virtually undetectable without the bubbles present. Using electrochemical impedance spectroscopy (EIS) and model fitting, it was shown that this effect occurs at the electrode interface. Theoretical derivation supported by potentiostatic voltage measurements indicated that a change in the electrode surface area in contact with the fluid was responsible for the effect. Optical micrographs were taken as a bubble along the electrode was pressurized. Using image analysis, the relationship of the change in surface area of the bubble correlated to the relationship of the change in impedance of the electrochemical cell (ECC). The results further demonstrated that the electrochemical response to pressure of a gelatin aerogel electrode was linear for the pressure range of 0 to1034 mmHg. This finding lends itself well for use in medical devices. A new device was invented along with a manufacturing process for an electrochemical pressure transducer (EPT). The EPT was subject to in vitro testing using simulated gastric fluid to create a baseline efficacy of the device for use in the gastrointestinal tract. Multiple design specific techniques were developed to improve sensor performance during physiological conditions.
Sponheimer, Chris, "Influence of Compressible Aerogel Electrodes on the Properties of an Electrochemical Cell" (2010). Electronic Theses and Dissertations. 620.
Received from ProQuest
Biomedical engineering, Mechanical engineering, Materials Science