Porous Monolith Structures in Microfluidic Devices

Laminar flow in the channels of microfluidic devices causes mixing to be diffusion-limited and slow. In order to improve mixing for fluorescently labeling proteins we create a passive mixer within a microfluidic channel by patterning an array of porous structures. These polymer monoliths are patterned directly within plastic chips via ultra-violet (UV) irradiation through a mask positioned over the desired area of the channel. Through optimization of the prepolymerization solution and irradiation time we demonstrate the ability to pattern plugs of monolith in 100-micrometer segments within 5 to 6 minutes of UV irradiation. Future work will include evaluating the resolution limits and testing a small library of structures for mixing efficiency.