| Dynalloy Inc, USA, manufactures shape memory alloys which are specially designed for use as actuators in related applications. This material facilitates movement, much like a solenoid or motor, for multiple cycles. These nickel-titanium alloys are produced as small wires, branded Flexinol�, which act as actuators that contract when electrically driven, much like little muscles, at a distance of approximately 4 to 5% when "on", and relax back into the original state when "off". This ability to flex or shorten is a characteristic of certain alloys that dynamically alter their internal structure at certain temperatures.
This product can be used in an extensive variety of technical applications. This capability includes specialist operations for electronics, such as micro clutches, spring loaded releases, and safety cut-offs. Flexinol� serves the vital field of medicine, with intravenous medicine, prosthetic limbs, surgical instruments, blood pressure test valves, and exoskeleton assistance all benefiting from such technology. In addition, the wires are utilised in the automotive industry for door locks, mirror controls, gear changing, remote releases and alarm devices, amongst a host of other automotive devices. Miscellaneous fields that benefit from Flexinol� include mechanical scanners, camera manipulators, robotic limbs, and camera shutters. Flexinol� actuator wire, when used within the guidelines, are able to obtain repeatable motion for tens of millions of cycles. If exposed to higher stresses or strains than intended, memory strain gradually decreases and operational motion is obtained for only hundreds, or a few thousand, cycles. Permanent deformation that occurs in the wire during cycling results from the stress imposed and the temperature under which the actuator wire is operating. Since temperature is directly related to current density passing through the wire, care should be taken not overheat the actuator wire.
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