Development of Microfluidic Chips and a Customised Flow Control System for use in a Label-Free Cytometer

Abstract: Conventional cytometry uses fluorescently labelled cells that are laborious and costly to prepare. Using a label-free technique, individual cells can be differentiated by light scattering patterns, a result of different physical attributes. This thesis describes the development of a microfluidic label-free cytometer. The key components include a microfluidic chip, a laser light scattering system for cell characterization, and a microfluidic flow control system. A PDMS microfluidic chip was developed and described in detail. A customised flow control system with sorting functionality was constructed to respond faster than commercial pumps. The linear relationship between applied pump pressure and average flow speed was confirmed experimentally, as well as a sorting flow response of 48.3ms or less. Results from laser light scatter experiments with different biological cells were presented, where scatter patterns for each cell type were visually distinguishable.