Patent ID: 6948800

Claim:
A normally closed fluid microvalve for controlling a pressurized fluid comprising: (a) a chamber, formed in a substrate, and having a fluid flow port; (b) opposing anchor edges supported from the substrate, said anchor edges defining a central plane; (c) a deformable element attached to the opposing anchor edges and having a central portion urged sealably against the fluid flow port, the deformable element constructed as a planar lamination including a first layer of a first material having a low coefficient of thermal expansion and a second layer of a second material having a high coefficient of thermal expansion, the deformable element formed to have a residual shape bowing outward from the central plane in a first direction away from the second layer and towards the fluid flow port; (d) apparatus adapted to apply a heat pulse to the deformable element, causing a sudden rise in the temperature of the deformable element, the deformable element initially bowing farther outward in the first direction, then, due to thermomechanical torque's acting at the opposing anchor edges, reversing and snapping through the central plane to bow outward in a second direction toward the second layer, opening the fluid flow port permitting the pressurized fluid to flow through the fluid flow port, and then relaxing to the residual shape, sealing the fluid flow port as the temperature decreases thereof.