Shape Memory Alloys (SMAs) are smart metal alloys (including Nickel-Titanium) that change shape dramatically when heated with electrical current. In wire form, the shape change is a silent, aggressive contraction, and the wire contraction provides usable stroke with very high forces. In fact, SMA has the highest force/weight ratio of any known motor, providing forces up to 350 times the actuator weight. SMA actuators are ideally suited to the operation of control surfaces, where small form factors and very low weight are driving requirements. We propose to develop an SMA driven Towed Array Control Module (SM-TACM) to demonstrate the superior capabilities of SMA devices in Naval applications. The module will employ hydrodynamic lift to control the depth and position of a towed array. The Miga SM-TACM lifting body is designed to be compatible with both buoyant and sinking arrays, and is capable of surface-start on a buoyant array, or vertical (nose-down) start of a negative buoyancy array. Finally, the SM-TACM lifting body acoustic noise will be lower than that of a turbulent, separated drogue system.
Benefit: There are numerous applications for high-strength linear electric actuators in the defense community including security locking systems, latch-release mechanisms, aircraft control-surface actuators, and remotely operated vehicles (especially UAVs). Robotic manipulators, rovers, and other exploration technologies can benefit significantly from these lightweight, high-force actuators with an extremely high force/weight ratio (currently over 350:1). Miga SMA actuators are compatible with ultra-high vacuum: made entirely out of high-temperature thermoplastics, Nickel-Titanium, and stainless steel (or titanium). There are no lubricants. The total part count is very low, enhancing reliability in any application. Also owing to their extreme low weight, they are nearly immune to high-g loads. They can be actuated very quickly (providing very high impulse), and operate on battery power. The medical industry provides the most pressing demand for modern, high force, linear electric actuators. The miniaturization of electronic components has fueled the desire for more portable equipment, and much of the diagnostic equipment in the medical industry today relies on motors, solenoids, and pneumatic actuators to move, latch, pump, or squeeze samples and subjects -in ever diminishing package sizes. There is a huge pent-up demand for assisted medical devices: those which require a human input, but also demand higher forces than can be applied by a single technician, or for long periods of time. The defense industry is an important market, requesting efficient electric actuators that can open and close weather-station doors in harsh environments, for instance. Security is becoming an increasingly important business sector, and there are numerous demands for integrated security solutions, including electronic latching, dead-bolting, assisted entry systems, and use as redundant mechanisms in biometric security systems.
Keywords: linear actuators, linear actuators, Nitinol, shape memory alloy, Displacement Multiplication, SMA actuators, Electric Actuators, Towed arrays
