NASA is on the brink of creating an aviation transformation— improved aerodynamic performance through the use of a new metal alloy that will enable aircraft wings to bend and adapt to flight conditions while in the air instead of remaining in a fixed position.
The accelerated development of shape memory alloys, a cutting-edge, smart metal that can bend, change shape and then return to its original state like a stretched rubber band, has come about through the work of NASA Materials Research Engineer Othmane Benafan and his team.
“Othmane has taken something that people have worked on in the laboratory and he has put it in the aerospace system,” said Rickey Shyne, director of research and engineering at NASA’s Glenn Research Center in Cleveland. “Whether moving aircraft wings or pointing satellites in space, shape memory alloys are a breakthrough technology.”
NASA, working with Boeing Research and Technology, successfully tested the new alloys at the Armstrong Flight Research Center in California during 2017 and 2018 using an unmanned aerial vehicle with wings that could fold between zero and 70 degrees up and down in flight.
“I don’t think we would be where we are today without Othmane,” said Dale Hopkins, associate program manager at the Glenn Research Center. “He has taken shape memory alloys from fundamental research to a flight demonstration on a real Boeing airplane.”
Benafan and his team also are using the wing from a supersonic jet to demonstrate the concept at a much larger scale.
The ability to move aircraft wings up and down in mid-air could, for example, enable a plane to adapt to changing flight conditions, save fuel and reduce the effects of turbulence and wind gusts. This concept has been studied for years, but implementation has been handicapped by the fact that conventional motors and hydraulic systems are heavy, bulky and rigid. Shape memory alloys could change that dynamic.
In addition to aviation, shape memory materials have been used in space on a small scale since the 1980s, including on NASA’s Mars Pathfinder Sojourner Rover, and for activating one-time antennas or deploying cargo. Benafan’s work could enhance space exploration through use of the alloys in different types of space vehicles and instruments.
Robert Carter, a NASA scientist, said Benafan developed “the first principled understanding of how these new shape memory alloys work and why they work, and based on that knowledge has been able to tweak certain elements and develop many new alloys.” The alloys were produced in small batches until Benafan developed new techniques, he added.
“One of the big things Othmane has done was to scale up,” Carter said. “We can now make very large shapes and sizes and structures out of these alloys, like he’s done with the folding aircraft wings.”
John Cavolowski, director of NASA’s Transformative Aeronautics Concepts Program, said Benafan is helping rapidly advance the science, having developed a database that enables other researchers to determine what elements of the alloys need to be changed so they can be put to optimal use.
Benafan’s work also has led to the creation of a new technology known as the Shape Memory Alloy Rock Splitters system, an environmentally friendly method for splitting apart rocks in a controlled manner without the use of explosives or hydraulics.
When an instrument made of the alloy is inserted into a close space, such as a drilled hole or a crack and then heated, it exerts a large force that breaks the rocks apart. As the alloy cools, it reverts to its original shape, at which point it can be extracted and used again. Space vehicles such as a rover can bring the material to use for better sample extraction while exploring planets and asteroids.
“Othmane came up with the idea to use the shape memory alloy (for rover rock collection) because it could allow our exploration efforts to gather a lot more science,” said Shyne.
Potential down-to-earth uses of the rock splitter include oil drilling, civil engineering, archeological digs, search and rescue operations, and military applications.
Benafan, who immigrated to the U.S. from Morocco at age 19, started out washing dishes at a Disney World hotel while attending college at night, taught himself English and eventually obtained a doctorate.
Working for NASA, Benafan said, is a “dream job.” He said he always has been fascinated by space exploration, loves to serve others and now has the resources, the support and the opportunity to advance science and American technology.