MULTIMATERIAL MULTILAYER FABRICATION OF MICROFLUIDIC DEVICES

Abstract

Microfluidics technology enables miniaturization, integration and automation of chemical and biochemical assays. Compared to conventional analytical tools, a microfluidic device requires small volume of samples and performs assays faster making it a suitable candidate for point- of-care diagnostic devices. Various fabrication techniques for microfluidic systems have been developed over past three decades to construct microchannels and microfluidics components such as valves, pumps and electrodes. However, most of these methods are either expensive and requiring cleanroom environment or limited to use of single or a few materials primarily due to differences in process conditions of various materials. Therefore, an easy and robust fabrication technique that is able to integrate different microfluidic components into a single device is highly sought. Xurography as a rapid prototyping tool was introduced over a decade ago for construction of microchannel. Although this technique has significant capability to pattern variety of materials, it has not been applied for important microfluidic components such as valves and electrodes. In this thesis, combination of xurography with lamination has been developed to integrate microfluidic components. Use of commercially available film in variety of materials such as thermoplastics, elastomers and metals significantly reduces the cost of fabrication. Also, these materials have different properties such as insulating, conductive, elastic, hard, soft, hydrophobic and hydrophilic providing unique functionality in microfluidic devices. Therefore, various applications such as fluid flow controll by active and passive valves, DNA electrophoresis, electrochemical sensing, electrokinetic mixing and heating are presented.