Design, analysis, fabrication, and testing of a multi-step enzymatic-cascade microsystem

This is the first known method to achieve polymerization using a microfluidic device through a multi-step, enzymatic process. This microdevice integrates chemical mixing, reaction chambers, and multiple fluid sample manipulations in a monolithic platform. Enzymatic Polymer Synthesis is a multi-step, cascading reaction, which requires more complex fluid manipulations than most simple microchips can offer. This complete system takes into account the multidisciplinary nature of microfluidics and biomaterials processing.;This research included the design, analysis, fabrication, and testing of a novel application-specific integrated microfluidics system to perform all of the operations for an enzymatic polymer synthesis. For high reliability, the entire system has no moving internal parts, with all of the passive components integrated on a monolithic chip. Better reactions are achieved by implementing a "Y" shape mixing channel over the conventional mixing "T" channel. The micro-components that were developed included waste-outlet embedded reaction vessels and unidirectional, passive check valves, which were capable of creating 5kPa pressure barriers by using only the capillary forces of the fluid. Fabrication of these devices took advantage of MEMS-based silicon micromachining, PDMS microcasting, and oxygen plasma bonding to create a low-cost microsystem.;In operation, the chip handles polymerization by using mildly selective enzymatic methods to covalently couple the primary hydroxyl group of ascorbic acid with methyl methacrylate monomers, followed by a second enzymatic reaction catalyzed by horseradish peroxidase to polymerize the monomer, yielding an ascorbic acid polymer within minutes. This low-cost device significantly reduced the time and materials required over conventional process. The final product will be useful in therapeutic and pharmaceutical applications as it contains ascorbic acid, an antioxidant.;This work presents a technology platform that could find use in a variety of enzymatic-reaction related research. It is especially suited for early stage experimental synthesis of new polymers. This system and technology could also be used in various areas of particle synthesis research, metabolic engineering, and pharmaceuticals development.