Design of a dielectrophoretic cell loading device

Abstract

In recent years there has been an increasing interest in studying individual cells, and structures that physically entrap one or few cells have been developed for this purpose, but the approaches to load cells into these structures leave a lot to be desired. This dissertation discusses the design of a device that loads cells suspended in a solution into microvials using a combination of dielectrophoresis and fluid flow, which offers significant advantages over previous loading approaches. The basic concept is to use fluid flow and dielectrophoretic forces to position a given cell above a given vial, within an array of similar vials, and then bringing the cell into the vial. The loading of several cells flowing in a channel into a vial in a matter of seconds is demonstrated.

The design of the loading device spurred the development of novel topics in the area of dielectrophoresis. The structures into which cells are loaded produce "parasitic cages". The effect of multiple electric fields and at multiple frequencies had to be explored to eliminate the parasitic cages, and new theory was developed to describe the phenomenon in a straight forward and convenient way. The design process of dielectrophoretic structures known as flow through sorters was simplified significantly using a method that relies on non dimensional analysis and a figure of merit. These topics investigated have broader applications than just loading cells into vials.

The dissertation demonstrates technologies and design and fabrication methods key to the cell loading design. The dissertation ends by describing the design of a device that can be implemented to load cells into vials on integrated circuit chips and outlining this device's expected characteristics and performance based on the theory and methods presented through the dissertation.