A PDMS pinch-valve module embedded in rigid polymer lab chips for on-chip flow regulation

A new dead-volume-free PDMS pinch microvalve has been designed, fabricated and characterized in this work for valving and flow regulation on rigid polymer lab chips as an embedded modular platform. The pinch microvalve is operated by compressing a microfabricated flexible channel with an external actuation force. The assembly of modular PDMS pinch microvalves within rigid thermoplastic microfluidic devices provides numerous benefits in realizing hybrid polymer lab chips with functionality to precisely regulate flow. Flow rates of the developed pinch microvalve were characterized with respect to the pinch valve channel dimension and the pinching displacement distance applied to the valve. Finally, a microfluidic system with a single channel that branches into four pinch-valved channels was realized and a novel scheme for simultaneously actuating all four valves with a single actuator was demonstrated. The microfluidic PDMS pinch valves developed in this work will have a variety of applications in microfluidic systems developed in rigid polymers.