Date of Award

Spring 5-20-2021

Level of Access Assigned by Author

Open-Access Thesis

Degree Name

Master of Science in Biomedical Engineering

Department

Biomedical Sciences

Advisor

Caitlin Howell

Second Committee Member

Mauricio Pereira da Cunha

Third Committee Member

Andre Khalil

Abstract

Small biomolecules can be challenging and expensive to isolate and manipulate, but they may be the key for developing more efficient diagnostic tools for the detection of biomarkers, such as those associated with pancreatic cancer. Pancreatic cancer has a survival rate of less than 10% five years after diagnosis. For this reason, the research and establishment of cheap, effective screening tools are highly desired. One promising method of screening is separating and identifying biomarkers in a patient’s blood that are indicative of pancreatic cancer. The purpose of this project is to develop a system using surface acoustic waves (SAWs), in conjugation with microfluidics and surface functionalization, to manipulate small molecules and droplets with the goal of enabling the system to isolate particles within the blood. The separation and manipulation are achieved by passing the targeted fluidic material, in this case blood, through a microfluidic channel on top of a SAW device. The SAWs are generated by using an array of interdigital transducers (IDTs) photolithographically printed on a piezoelectric crystal to convert the electrical signal into acoustic waves. The SAW propagates, guided at the top surface of the material, and interacts with the fluid, exerting a force on the fluid and on particles in solution. Using open microfluidics to manipulate fluid droplets as an alternative to a continuous flow stream in an enclosed microfluidic channel is also an option. Functionalizing the surface using a fluorinated silane and coating with a fluorinated oil creates a liquid layer for easy droplet manipulation. The results of implementing this procedure shows dewetting of the oil layer, but despite this the liquid coating did provide a surface hydrophobic enough to allow for easy droplet sliding. This procedure combined with a heat source allows for concentration of particles at specific locations for easier particle detection. The development of the device discussed is expected to help yield a new and consistent approach to biologic particle manipulation methods that is both compact and more sensitive to facilitate the detection of diseases such as pancreatic cancer long before symptoms appear.

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