Novel photopolymers and innovative technologies for the fabrication of microfluidic devices

Microfluidic devices can process and manipulate small amounts of fluids (nanoliters), using channels with a diameter of tens to hundreds of micrometers. One can effectively scale down chemical and analytical reactions to a microscopic size, reduce the quantities of reagents involved, increase the selectivity, efficiency and speed of the process, and minimize the involved costs. Therefore microfluidics represents an emerging technology in many areas of chemistry and biotechnology. Microelectronics provided the technologies suitable for the fabrication of the first microfluidic devices made of silicon and glass, but these materials have soon been displaced by polymers. However, some problems still exist regarding fabrication process, integration of microcomponents, and compatibility toward the reaction media. Consequently, the development of new materials or modification of existing polymers is still a key issue to guarantee the full success of microfluidic devices and their spreading on the market. Moreover an important aspect for the widespread availability of microfluidics is the optimization of new technologies for manufacturing devices. Only fabrication methods that guarantee a mass production of chips at low cost and that can be easily applied to different materials allow microfluidic devices to become versatile tools. It is therefore essential to explore new polymeric materials with properties suitable for specific applications in microfluidics and to develop rapid and low cost microfabrication technologies that do not limit the achievable features. Testing new polymeric materials and developing innovative fabrication technologies can certainly widen the application field of microfluidics. The research work carried out concerns the development of novel polymers suitable for the fabrication of microfluidic devices via innovative methodologies based on photopolymerization. First we prepared different UV cured polymers by photopolymerization of radical reactive systems, and some of them were selected (depending on their physico-chemical properties) for manufacturing microfluidic devices. For the fabrication of microfluidic devices, photopolymerization was coupled with lithographic techniques in order to develop direct or replicating methods. The different technologies based on UV curing we optimized allowed the fabrication of microfluidic devices in short times, without using solvents, and at room temperature. The obtained devices were then tested for chemical and biological microfluidic applications.