Part of the show Naked Science Questions and Answers
Researchers at MIT have found a way to take the drag out of flying, at least for the wings if not the passengers. Aeroplanes are currently controlled by wing flaps that hinge up and down, which change the shape of the wings and alter the flow of air over the surface. The major disadvantage of wing flaps is the creation of a corner which leads to the formation of drag, reduced speed and decreased manoeuvrability. The problem could be solved by using a material that changes shape smoothly, allowing the wing to bend without drag. But until now it seemed that such a material had evaporated into thin air. However, scientists at MIT may have discovered a solution. They noticed that the compounds used to store energy in lithium rechargeable batteries change shape as they charge and discharge, which occurs due to the movement of ions in and out of the material. The researchers took advantage of this gentle bending and incorporated the material into the wings. In addition to changing shape, the material is light and can even morph under large forces. This means that the pilot can still control the plane even when heading towards the ground at high speed. Although a breath of fresh air for aerodynamics research, practical applications for the material are still in the development stages. However, the high flying scientists hope to have made a shape-morphing helicopter blade by the end of the year.