A new actuator for silicon micro-valves has been developed and tested. A thin film shape memory alloy provides for large deflections with high speed, low power, and small size. The actuator is batch fabricated with planar processes.

Thin film shape memory alloy has been integrated with silicon in a new actuation mechanism for micro-electro-mechanical systems. This paper compares nickel-titanium film with other actuators, describes recent results of chemical milling processes developed to fabricate shape memory alloy micro-actuators in silicon, and describes simple actuation mechanisms which have been fabricated and tested.

Microns-thick sputtered films of TiNi shape memory alloy deposited on silicon substrates have been capable of forceful electrical actuation. Present devices are made to millimeter scale. Research under way concentrates on reducing component size to hundreds of microns. Combined with springs, orifices, and ports, these devices made miniature valves for pneumatic and fluid control. Design, fabrication, and flow characteristics of a valve of 0.25 cm3 in size are discussed. Other applications for this technology will also be addressed, including microswitches and movable micromirrors.