Researchers show concept for shape-changing airplane wing

Scientists from NASA and MIT have shown a new wing design that is flexible and can change shape during flight. The concept would be relatively easy to produce and should, for example, make today’s butterfly valves, hydraulics and cables superfluous.

The wing consists of hundreds of small, identical pieces and has been tested in a wind tunnel. The concept wing can change shape to control flight, eliminating the need for moving surfaces such as ailerons. According to the researchers, this design can speed up aircraft production, improve flying itself and increase efficiency.

To allow the entire wing or parts of it to change shape, a mix of rigid and flexible components is used and placed in a structure. These small, identical, triangular parts are linked together in an open, lightweight framework, over which a thin layer of polymer is placed.

According to the researchers, the result of this is that the wing is much lighter. This means that aircraft equipped with this will also be much more energy-efficient than the relatively heavy wings of today’s aircraft. Because the design is based on a structure that can be compared to a structure made of matchsticks, the wing mainly consists of open space. Based on this, the researchers speak of mechanical metamaterial that combines the structural stiffness of rubbery polymer with the extreme lightness and low density of airgel.

In principle, it is possible to integrate motors and cables into the design to allow for the deformation of the wing, but the researchers instead designed a system that automatically responds to the changes in the aerodynamic conditions of a flight by changing the shape. to adjust. “We are able to produce the exact same behavior that pilots now actively do, but we did it passively,” said lead researcher Nicholas Cramer.

The scientists’ design could change the traditional shape and concept of today’s commercial airliners, because the wings in the concept do not require their own parameters for all phases of flight. This means that the wing concept does not have to be a compromise, as is the case with current wings.

The underlying concept was demonstrated a few years ago in the form of a one-meter wing. The current concept is a five-meter wing, which makes it comparable to the wing of a single-seat aircraft. At the moment, the wing was assembled by hand, but according to the scientists, this can be done quite easily autonomously by robots in the long run, according to the scientists.

In the previous concept, the individual parts were ‘cut’ into pieces with a water-cutting system, which took several minutes to create each part. In the new concept, injection molding and polyethylene are used in a complex 3D mould. Each part is produced in 17 seconds. This is significantly faster than with the previous concept, so that the researchers refer to it as a ‘manufacturing method’. The parts are cheap, so that in theory the concept can be used for mass production.

The research has been published in the scientific journal Smart Materials and Structures under the title Elastic shape morphing of ultralight structures by programmable assembly.