Developed primarily by engineers from NASA and MIT, the wing is made from thousands of triangular components with matchstick-like struts, bolted together in a lattice framework. This lattice is then covered in a thin layer of polymer material similar to the struts. The resulting wing structure is comprised mostly of empty space, forming a mechanical meta-material that integrates the stiffness of a rubber-like polymer with the lightness and low density of an aerogel. According to the analysis, the wing has a density of just 5.6kg per cubic metre.
 
What’s more, the form of the wing behaves passively to its environmental forces, with the stiffness in different struts carefully calibrated to achieve the ideal effect. Sections of the wing bend in response to the different phases of flight, providing a more best performance at take-off, cruise and landing. The research is presented in the journal Smart Materials and Structures.
 
“ We’re able to build efficiency by matching the shape to the loads at separate aspects of attack,” said lead author Nicholas Cramer, a research engineer at NASA Ames in California. “ We’re able to produce the exact same behaviour you would do actually, but we did it passively.”
 
A 1m version of the wing was developed a few years ago to verify the underlying principle, with a waterjet used to fabricate the individual components. This present research saw the team create a 5m prototype, using injection moulding to greatly speed up the manufacturing process. The struts still had to be put together by hand, but the team believes this step could be automated using assembly robots, and this is the subject of an upcoming research project. As the wing is made from thousands of sub-units, it also opens up the possibility of entirely new aircraft designs.
 
“You can make any geometry you want,” said Benjamin Jenett, a graduate student in MIT’s Centre for Bits and Atoms. “The fact that most aircraft are the same shape” — a tube with wings — “is because of expense. It’s not always the most efficient shape.”
 
During testing at NASA’s high-speed wind tunnel at Langley Research Centre, the wing performed slightly better than predicted, according to Jenett. He also claims the same fabrication system for the wing structure could be used to build blades for wind turbines, facilitating on-site assembly and avoiding the problems associated with transporting ever-longer blades.



This article is originally posted on Tronserve.com