Alloy tested to create foldable wings for supersonic drone

NASA and Boeing have tested a drone that can hit incredible speeds due to a material innovation that allows the wings to dynamically change shape and position based on flight needs.

The principle of reducing drag on a plane is not new, but the new design shows a significant improvement in overall performance for flights of this type. Jim Mabe, a researcher at Boeing, said: “From the time we started initial testing here at Boeing, up to the flight tests, the material behaved consistently stable, and showed a superior performance to previous materials.”

The material is called shape memory alloy, and while the concept has been around for almost a century, these new capabilities are ground-breaking. Shape memory alloy can be deformed and reshaped while at room temperature, but when they are heated up they return to their original position. The metal changes ‘phase’ at a very specific temperature, meaning the actuators don't need to heat or cool the object very much in order to get it to respond. Shape memory alloys are also extremely durable and can return to their original shape even after a significant stress has been placed on them. NASA’s drone was able to shift its wingtips from 0 degrees to 0 degrees in its successful flight tests.

The alloy was moulded into an actuator, allowing the wings to change shape mid-flight to properly adjust for wind and speed conditions. The device used to change the temperature of the alloy is significantly lighter and more compact than motors and joints, allowing machinery to fit in a much smaller space.

Because the alloy is extremely light, it can be placed anywhere on the plane. Using it in actuators allows engineers to replace what would otherwise be bulky and heavy steel machinery, significantly reducing the overall weight of the craft. According to NASA, crafts with this material may weight up to 80% less than current crafts.

Weight has been a huge concern in aircraft design since the Wright Brothers, who crafted the first human-piloted flying machine and had to create their own engine because existing ones were made of steel and were too heavy. The development of super light materials makes way for impressive new designs. Not only does this allow for smaller aircraft to reach supersonic speeds, but it could affect the design of larger subsonic aircraft too; lighter aircraft are more fuel efficient, and more moving parts means they will be able to go more places and offer higher controllability in the air.