Thesis
Engineered surfaces for actuation and sensing application
Washington State University
Master of Science (MS), Washington State University
12/2015
Handle:
https://hdl.handle.net/2376/105165
Abstract
This thesis focuses on the engineered surfaces for actuation and sensing application. The first project focuses on the fabrication of an active micromixers and the analysis of mixing inside micromixers. Rapid and homogeneous mixing inside a microfluidic channel is demonstrated via the reverse piezoelectricity effect induced by the oscillation of very strong in/out flow form the nozzle. By optimizing the design of the geometry and experiment parameter, excellent mixing performance and fast mixing speed can be achieved in a simple device, making our reverse piezoelectricity as part of micromixer a promising candidate for a wide variety of applications. The second project investigates the development and characterization of a hydrogen gas sensor. The independent testing and validation of a packaged, electrochemical prototype hydrogen sensor is reported. Custom electronics were developed with the data acquisition system to assess sensor performance. The system controlled and monitored humidity, pressure, and hydrogen gas concentration and introduced interference gases such as methane, carbon dioxide, carbon monoxide and ammonia. The hydrogen sensor was made of Indium Tin Oxide and Platinum electrode and Yttria-Stabilized Zirconia (YSZ) electrolyte. Testing showed a fast response to H2 with exceptional low-level sensitivity (0.005-2%) and high signal-to-noise ratio. A minimal deviation in sensor response to changes in ambient conditions such as humidity was observed along with minimal response to interference gases. The hydrogen prototype sensor was operational and insensitive to variations in oxygen partial pressure down to approximately 0.2% oxygen, while anaerobic conditions caused the sensor to become inoperable. The tests indicate that the sensor prototype will effectively function and trigger event alarms and continue to function unless anaerobic conditions are established. It is envisioned in future to develop a different working electrode based on a more robust material such as La1- xSrxCrO3 for applications where substantially harsher environments (absence of oxygen supply, higher altitudes, and higher atmospheric pressure) may be experienced.
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Details
- Title
- Engineered surfaces for actuation and sensing application
- Creators
- Jie Zhou
- Contributors
- Praveen K. Sekhar (Chair)Tutku Karacolak (Committee Member) - Washington State University, Engineering and Computer Science (VANC), School ofJong Hoon Kim (Committee Member) - Washington State University, Engineering and Computer Science (VANC), School of
- Awarding Institution
- Washington State University
- Academic Unit
- Electrical Engineering and Computer Science, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Number of pages
- 68
- Identifiers
- 99900525272301842
- Language
- English
- Resource Type
- Thesis