Paraffin actuated surface micromachined valves

A new, active, normally-open blocking microvalve that uses the thermal expansion of a sealed, thin paraffin patch for actuation has been fabricated and tested. The entire structure is batch-fabricated by surface micromachining the actuator and channel materials on top of a single substrate. The paraffin actuated microvalves are suitable for applications requiring many devices on a single die, low processing temperatures, and simple, nonbonded process technology. Gas flow rates in the 0.1-2.0 sccm range have been measured for several devices with actuation powers less than 50 mW.