FLEXINOL® actuator wire is a trade name for shape memory alloy actuator wires. Made of nickel-titanium, these small diameter wires contract (typically 2% to 5% of their length) like muscles when electrically driven or heated. This ability to flex or shorten is a characteristic of certain alloys, which dynamically changes their internal structure at certain temperatures.
The idea of reaching higher temperatures electrically came with the light bulb but, instead of producing light, these alloys contract by several percent of their length when heated and can then be easily stretched out again as they cool back to room temperature. Many tasks currently accomplished with small motors or solenoids, wax actuators, piezo, and bi-metals can be improved with FLEXINOL® actuator wires.