Date on Master's Thesis/Doctoral Dissertation

5-2020

Document Type

Master's Thesis

Degree Name

M. Eng.

Department

Bioengineering

Degree Program

JB Speed School of Engineering

Committee Chair

Kopechek, Jonathan

Committee Member

Roussel, Thomas

Committee Member

Yaddanapudi, Kavitha

Author's Keywords

ultrasound; microfluidic; Louisville; computational model; acoustic; transducer

Abstract

The objective of this thesis is to develop a mathematical model characterizing the behavior of a microfluidic sonoporation device in order to understand how standing wave conditions influence molecular delivery to cells and determine whether the model predicts device performance. A prior model based on an ultrasonic separation cell that uses standing waves to separate particles is adapted for translation to the microfluidic device. This study generates data on acoustic pressure profiles across the cell as well as identifying optimal driving frequencies. This model is validated and the equations and methods for developing this model are translated to the microfluidic device. An investigation into the variation of cell layer parameters and driving frequencies is conducted to understand their influence on acoustic pressure profiles and resonant frequencies across the cell. These data are compared to experimental trials which measure cellular uptake of fluorescence when driven through the microfluidic device exposed to different ultrasound frequencies. Results suggest that the 6 MHz driving frequency generates the largest pressure profile across the cell but does not correlate with high molecular delivery efficiency during experimental trials. Additional conclusions regarding the acoustic pressure profile dependency on density, thickness, and speed of sound within the layers show a significant effect for specific frequencies. The large variation in results for differing material and geometric parameters shows the need for further refinement of these parameters for the laboratory device. Once additional experimental trials are conducted, more iterations of the model are tested, and cell parameters are more precisely determined, the translated model can be used for extensive characterization of acoustic pressure profiles across the cell for future design iterations of the device.

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