THE SCHOOL OF MATERIALS SCIENCE AND ENGINEERING 

GEORGIA INSTITUTE OF TECHNOLOGY   

Under the provisions of the regulations for the degree 
 

DOCTOR OF PHILOSOPHY 
 

on Tuesday, November 8, 2022

11:00 AM

via

Zoom Videoconferencing

https://gatech.zoom.us/j/94991934416?pwd=clp0YlhxZWVoWjdualducHFqOHNXUT09

will be held the

DISSERTATION PROPOSAL DEFENSE 
 
for

Zhaonan Liu

" Impedance-Based In-Line Cell Growth Sensors for Cell Manufacturing"

Committee Members:

Prof. Ben Wang, Co-advisor, MSE/ISyE/ME

Prof. Chuck Zhang, Co-advisor, ISyE

Prof. Donggang Yao, MSE

Kan Wang, PhD, ISyE

Prof. Rosario Gerhardt, MSE

Abstract:

Cell manufacturing is a fast-growing industry as cell therapies show their unparalleled capabilities to treat diseases that humans have never found a cure. Cell density is a critical quality attribute (CQA) in the cell manufacturing process that serves as a key decision-making factor. Impedance/dielectric spectroscopy (IS/DS) has been widely used for biomass monitoring since the 1930s. The development of high-performance computing devices and artificial intelligence in recent decades has expedited the measuring and analysis of IS/DS, enabling this technique to monitor biomass in real time. However, there is still an abundance of mysteries unrevealed and opportunities unexplored in this complicated technique. The mechanism of low-frequency dielectric dispersion (LFDD) is not fully clear to date. The applications of IS/DS in intricated bioreactors, such as hollow fiber bioreactors, are seldom discussed.

This work is based on a comprehensive understanding of IS/DS and its application in biomass sensing and focuses on the underexplored aspects of this technology. Novel theoretical, experimental, and analytical methods have been developed in this work. Those new methods also have the potential to be applied to other sensing scenarios.