Novel architecture for entrapment of elastomeric membranes in microfluidic systems

Graduation date: 2005This thesis presents a novel microlamination architecture that enables the large scale integration of valves into low cost micro energy and chemical systems via membrane entrapment. Polycarbonate layers embossed with microfluidic channels were bonded by ultrasonic welding of raised embossed protrusions that penetrate though the PDMS membranes. The bonding pressure compresses the membranes and forms a conformal seal across the interface of the PDMS and polycarbonate effectively sealing the fluidic channels up to 22 PSI fluid pressure. When deflected into the microchannels by pneumatic pressure the membrane acts as proportional flow control and shut off valves. The architecture gives additional design freedom in the selection of materials since membranes can be entrapped in polymers that are incompatible for traditional\ud bonding methods. The combination of high modulus polycarbonate layers with low modulus PDMS layers increases spatial intensification over monolithic PDMS microdevices that rely on bulk for rigidity. The ability to number up the layers for high throughput was demonstrated as well as the potential for two way valves and pumping mechanism