Researchers from MIT and NASA have designed a flexible “morphing wing” system made of carbon fiber reinforced plastic (CFRP) that draws inspiration from the twisted wings from the Wright Brothers’ first powered flight.
The wing design is based on a system of tiny, lightweight composite subunits called “digital materials” that could be assembled like Legos by a team of small specialized robots, and ultimately could be used to build the entire airframe. MIT says the digital materials can be assembled into “a virtually infinite variety of shapes.”
The individual pieces are strong and stiff, but the exact choice of the dimensions and materials used for the pieces, and the geometry of how they are assembled, allow researchers to customize the flexibility of the final shape. For the initial test structure, the goal was to allow the wing to twist in a precise way that would substitute for the motion of separate structural pieces.
The wing is covered by a “skin” made of overlapping pieces that might resemble scales or feathers. MIT says this approach could simplify the manufacturing process and reduce fuel consumption by improving the wing’s aerodynamics and agility. The skin is made from 0.127-millimeter thick Kapton (polyimide film), cut into strips on a CO2 laser cutter.
According to Neil Gershenfeld, director of MIT’s Center for Bits and Atoms, researchers have been trying for years to create similar technology, but have failed to make an impact because their designs relied on deforming the wing through the use of mechanical control structures within the wing itself, which weighed it down and canceled out any potential aerodynamic advantage it would have. Gershenfeld says MIT and NASA’s design represents a different approach.
“We make the whole wing the mechanism. It’s not something we put into the wing,” he explains. With the new approach, the whole shape of the wing can be changed and twisted uniformly along its length by activating two small motors that apply a twisting pressure to each wingtip.
MIT notes that the design could be used for more than just aircraft.
“The broader potential in this concept extends directly to skyscrapers, bridges, and space structures, providing not only improved performance and survivability but also a more sustainable approach by achieving the same strength while using, and reusing, substantially less raw material,” said Gonzalo Rey, chief technology officer for Moog Inc., a precision aircraft motion-controls company.