Programmable Control Of Non Droplet Electrowetting Microfluidics

Microfluidics is a broad research field that encompasses applications for the medical, chemical, industrial and environment industries by leveraging the ability to control and manipulate micro-scale volumes of fluids. Most applications involve some sort of sensing capability for the presence of specific biological, chemical, or mineral compounds which has been termed Lab-on-a-chip(LOC). This refers to the miniaturization of standard laboratory analysis systems on to a single device to allow for faster yield times, reduced reagent and sample use and overall reduced costs. There are currently two primary fluid handling methods used involving fixed-channel, continuous flow or discrete droplet manipulation. Fixed-channel microfluidic devices have been proven to be reliable for several LOC applications, however, there is no ability to reconfigure or repurpose a device without a complete redesign and fabrication. The second handling method, known as digital microfluidics, uses electrical stimuli to move and manipulate individual droplets over an array of electrodes. By using this method, reconfigurability can be realized simply by changing a sequence of droplet(s) movements and therefore, a single platform can be used for a multitude of LOC applications without a complete device redesign. To further the overall capabilities of a digital microfluidic platform, the ability to control and hold some fluidic shape without an applied voltage adds not only bistability to the system, but can be advantageous for reduced energy consumption, extra functionalities and improved fluidic control. This also allows for simple displays applications to be realized. Presented in this dissertation is a cross-platform digital microfluidic device developed for both LOC and simple displays applications which utilizes an electrowetting grid array and Laplace barriers for bistability. Materials improvements, electrical control methods and the ability to perform all necessary tasks for both types of applications were developed and will be demonstrated throughout.