Flying into the Future

Among the exotic "smart" materials being developed by the Morphing Project, shape-memory alloys are relatively ordinary.

Imagine seeing a bullet shot through a sheet of material, only to have the material instantly "heal" behind the bullet! Remember, this is not science fiction. Self-healing materials actually exist, and LARC scientists are working to unravel their secrets.

NASA This thin, flexible film contains a piezoelectric material that responds to the bend by producing a voltage that's detected by the electrodes seen at the bottom left of the image.

"What we did at NASA-Langley was basically dissect that material to answer the question, 'how does it do that?'" McGowan said. "By doing so, we can actually get down to computational modelling of these materials at the molecular level."

"Once we understand the material's behaviour at that level, then we can create designer 'smart' materials," she added.

LARC is also developing customised variations of piezoelectric materials. These substances link electric voltage to motion. If you contort a piezoelectric material a voltage is generated. Conversely, if you apply a voltage, the material will contort.

Scientists can use such properties to design piezoelectric materials that function as strain sensors or as "actuators" -- devices that create small motions in machines, like the moving of wing flaps.

Combined with micro-electronics, these materials could lead to a radical advance in airplane design.

"When we look 20 years into the future, we see airplanes that have distributed self-assessment and repair in real time," McGowan said.

"To make this technology possible, you would need to distribute these actuators and sensors throughout the wings. That's similar to how the human body operates. We have muscles and nerves all over our bodies -- so we are aware of what's happening to our bodies and we can respond to it in a number of ways."

The resemblance to biology doesn't end there. One avenue of Morphing Project research is to examine how nature does the things that it does well. Scientists hope they can learn lessons from this tutelage to improve their own designs.

"Nature does some things that we can't even get close to doing. Birds are so much more manoeuvrable than our airplanes are today. Birds can hover, they can fly backwards and sideways. And insects -- oh forget it! -- upside down, loop-de-loop, all sorts of things. We can't even get close to that [yet]," McGowan said.