Peltier-actuated microvalve performance optimization

Valves for microfluidic systems have, for various reasons, proven to be difficult to fabricate, cumbersome to operate, and/or unreliable. We have explored the performance of a novel microfluidic valve formed by creating a flow channel past a Peltier junction. When the Peltier junction is used as a thermoelectric cooler it is possible to freeze the fluid in the valve, forming an ice plug that blocks flow through the valve. This type of valve is fundamentally leak-free, has no moving parts, and is electrically actuated. We have fabricated several experimental prototypes and evaluated their performance. We find that they are reliably capable of closing in less than 100 ms, and of opening substantially faster.