Oxygen radical-driven surface modification of polycaprolactone-filled glass microfiber media: Probing the surface chemistry of wicking microfluidic devices

摘要

Cost and complexity are key factors in designing microfluidic devices for broad application. Therefore, the development of a simple, inexpensive, and easily manufactured fabrication technique that does not require expensive chemicals or instruments is necessary. We have successfully demonstrated the use of long-lived oxygen radicals for the fabrication of membrane-based microfluidic devices on polycaprolactone (PCL)-filled glass microfiber (GMF) membranes. These devices may incorporate complex multidimensional (2D and 3D) microfluidic pathways on a single PCL-filled GMF membrane. Selective exposure to oxygen radicals generated in a homebuilt oxygen plasma exposure system was employed to pattern the flow path; radical exposure of the polymer-filled substrate altered the physical and chemical properties of the surface, affecting wettability. To the best of our knowledge, this is the only wicking microfluidic device fabrication technology that is capable of generating both 2D and 3D microfluidic pathways in a single membrane; hence, it has many potential applications. Investigations were conducted to probe the effects of oxygen radical exposure in order to provide a more quantitative understanding of the process. These findings will help expand the utility of the selective oxygen radical exposure-driven fabrication technology.