Shape-Shifting Carbon Fiber Can Be Used in Aerodynamics, Robotics, and More
Imagine seeing wind turbine blades changing shape to maximize their efficiency, or airplane wings moving by themselves without the use of hydraulic rudders or ailerons.
These are only two of the great uses a new carbon fiber material could bring to life thanks to a team of researchers in Sweden. The KTH Royal Institute of Technology researchers have unveiled their proof of concept study and published it in the Proceedings of the National Academy of Sciences of the United States of America (PNAS).
The new solid-state carbon fiber composite unveiled by the KTH Royal Institute of Technology researchers is capable of changing shapes thanks to electronic impulses.
Co-author of the study, Daniel Zenkert, explained that the material demonstrates all the useful properties of shape-morphing materials. But, it does so without any of the issues other projects have encountered, such as weight and insufficient mechanical stiffness.
"Shape-shifting technologies are typically used in robotics, satellite booms, and more thanks to systems with heavy mechanical motors, hydraulic and pneumatic pumps, or solenoids" said Zenkert. These types of mechanical systems are known as "parasitic weight" and cost a lot to maintain.
One way to keep the cost minimal, as well as steering clear of heavy-duty mechanical systems is to use solid-state morphing materials.
Zenkert explained "We have developed an entirely new concept. It's lightweight, stiffer than aluminum and the material changes shape using electric current." The material can produce big deformations and can hold them without any extra power, even if it is done at low rates, he mentioned.
The team's composite is made up of three layers. Two of these layers are commercial carbon fiber doped with lithium-ions on either side of the thin separator. Adding electric current enables the lithium-ions to move from one side to the other, causing the usually-straight material to bend. Simply reversing the current enables the material to go back to its previous unbent state.
"We have for some time worked with structural batteries, such as carbon fiber composites that also store energy like a lithium-ion battery," Zenkert said. "Now we have further developed the work. We expect it lead to completely new concepts for materials that change shape only by electrical control, materials that are also light and rigid."
Now you know what to use when building your very own airplane wings.