Dilute aqueous solutions of poly(ethylene oxide)x-poly(propylene oxide)y-poly(ethylene oxide)x triblock copolymers undergo reversible gel formation at elevated temperatures. This effect can be effectively used for active and passive flow control in microfluidic devices, where the gel phase can block the flow channel partially or entirely. Heat transfer occurs fast through the typically small width of a microchannel resulting in a fast valve response time. A novel micromixing concept has been developed based on active microvalves.
Project end date: 08/31/05