Date of Award


Document Type



Santa Clara : Santa Clara University, 2016.


Bioengineering; Mechanical Engineering

First Advisor

On Shun Pak

Second Advisor

Unyoung Kim


In both developed and developing countries, there is a need for a fast diagnostic system to detect pathogens within a fluid sample. In developing a microfluidic platform, which utilizes a microfluidic chip and an optical detection method, doors may be opened for new methods of determining pathogen concentration in fluid. Most biological reactions are not instantaneous. A flow-controlling mechanism with no power requirement may be implemented in the microfluidic platform. As a proof-of-concept, our device uses a microfluidic chip, smartphone, and microlens to detect E. coli concentrations in water. The detection method is based on the latex agglutination assay which relies on visual observations and judgment to determine the presence of pathogens in the water sample. Our approach provides a quantification of the traditional latex agglutination output, and the lower detection limit (105cells/mL) is competitive with that of the traditional agglutination method. In developing such a platform, a cheap and effective detection test for people in developing countries can be available worldwide for easy determination of whether or not a fluid sample is safe for use, and with several modifications, this platform could potentially be used to detect different pathogens, simultaneously.