Thesis
An investigation into the pumping properties of diatom biosilica thin films
Washington State University
Master of Science (MS), Washington State University
05/2020
DOI:
https://doi.org/10.7273/000004088
Handle:
https://hdl.handle.net/2376/124846
Abstract
The accurate distribution of liquid in microfluidic devices is of paramount importance for correct functionality. Automated insulin delivery systems, particle separation devices, and certain chemical and biological sensors require specific flow rates to perform optimally. To accomplish the accurate and precise transport of liquid, a variety of microfluidic pumps have been developed, each with their own positive and negative attributes. A simple yet effective microfluidic pumping technique that has been studied over the last several decades mimics the same techniques plants use to transport liquid throughout their root systems by coupling capillary action with evaporation. Capillary action is used to fill a microfluidic device and drive fluid toward an orifice, while evaporation is used to maintain a continuous flow rate toward the orifice once the capillary network is filled. Specific constraints on the reservoir-orifice relationship are addressed in the theoretical section, but the orifice itself is typically an open capillary or a porous material capable of providing strong capillary pressure because of small pore spacing coupled with hydrophilic properties. Super-hydrophilic diatom biosilica thin films are ideal porous materials that can provide strong capillary pressure in a capillary-evaporation (CE) pump, and recent studies have demonstrated their ability to achieve near single-molecule detection of chemical and biological compounds in analyte solutions using microfluidic surface enhanced Raman spectroscopy (SERS). By coupling the detection and pumping properties of diatom biosilica, a simple and cost-effective device can be developed for widespread application. This thesis attempts to quantify the expected pumping properties of diatom thin films as a precursor to the creation of a self-pumping SERS device. The impacts of film size and temperature are measured in relatively stable ambient conditions and compared to a variety of theoretical models. Film improvement, pump limitations, and mathematical model attributes and deficiencies are addressed to maximize device detection levels.
Metrics
Details
- Title
- An investigation into the pumping properties of diatom biosilica thin films
- Creators
- Hunter Maxsam Jarrett
- Contributors
- Hua Tan (Advisor) - Washington State University, School of Engineering and Computer Science (VANC)
- Awarding Institution
- Washington State University
- Academic Unit
- School of Engineering and Computer Science (VANC)
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University
- Identifiers
- 99900890787801842
- Language
- English
- Resource Type
- Thesis