SMART TECHNOLOGY: NASA’s MORPHING PROJECT

BY CARYN ANSCOMB

"Birds are so much more maneuverable 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." Anna McGowan, program manager for the Morphing Project at NASA's Langley Research Center

(STARpod.org) -- NASA’s Morphing Project might on first glance appear to be something straight out of the realms of science fiction, with talk of smart materials able to morph and self-heal, but this is the real vision of next generation breakthrough vehicle technologies.

Current experimentation is proving incredibly exciting. “This is technology that most people aren't aware even exists.” says Anna McGowan, program manager at NASA’s Langley Research Centre (LaRC).

The team working on the Morphing Project at LaRC have been testing materials with highly unusual properties. These include materials which have the ability to bend on command, ‘sense’ pressure, transform from liquid to solid when placed in a magnetic field and shape-memory polymers. The primary shape memory materials in use are alloys like Nitinol, which have the stiffness of steel but can return to its previous shape when heat is applied, the original shape having been ‘trained’ into the alloy.

Perhaps more incredibly, the Science team have been working on ‘intrinsically smart’ materials which can perform self-diagnosis and self-repair.

By ‘back-engineering’ these materials the team have managed to peel back to their molecular level. As the materials behaviour at the molecular level becomes fully understood, ‘designer smart’ materials will be developed for future application in a number of fields, not least aerospace, where we might see the development of distributed self-assessment throughout the wings and body of craft with self-repair properties. The ‘self-healing’ materials are made of long-chain molecules called ionomers which react to penetration, such as a bullet, by closing behind it. The implications of this technology for space flight are tremendous.

If you think this study is more akin to studies in biology you wouldn’t be far off. Biomemetics is the study of and learning from nature. LaRC scientists study nature to better understand how birds and insects achieve their high degree of efficiency and manoeuvrability. These observations alongside the development of smart materials will eventually see the development of highly versatile craft in the form of light weight structures with flexible actuators in the wings and nerve-like sensors throughout the ‘skin’ of the craft. These sensors would be linked back to a central computer, ideally by molecular wires, formed from elongated molecules some of which naturally self-assemble into useful configurations.

DARPA (Defense Advanced Research Projects Agency) has been developing new piezoelectric actuators in what they call the Compact Hybrid Actuators Program (CHAP). CHAPs are highly efficient and small actuators which can sit in small spaces within the wing of aircraft. They can operate at low frequencies for periods from tenths of a second for control forces or several minutes to move the wing to a new configuration.

A complementary area of research covers gossamer materials, which are ultra-thin films that might be used for antennas or photovoltaic panels, in place of bulkier components in current use.

Composite materials, such as carbon-fibre, are already in use helping to bring weight down in aerospace designs, without compromising strength. However, another form of carbon called ‘carbon nanotube’ has taken the interest of NASA scientists over the last few years. The molecular structure of the nanotube makes it far stronger than the best composites which have 3 to 4 times the strength of steel, whereas nanotubes have around 600 times the strength of steel.

Carbon Nanotubes (CNT) were first discovered in 1991, and were primarily grown by laser ablation and carbon arc techniques. Both produce single wall carbon nanotubes (SWNTs) in small quantities. The search has been on to discover and develop a reliable source for the production of large quantities of SWNTs. In the last few years an effective alternative in the form of chemical vapour deposition has effectively been put into use.

To date, 2006, no research group has been able to precisely control the growth of the CNT diameter, though extensive research and experimentation continues.

These ‘smart’ materials and technologies combined may well herald a future of morphing aeroforms allowing bird-like control of aircraft flight and self-diagnostic, self-repairing space-craft.

With the current advances in nanotechnology the Sci-fi dream of mind/machine interfaces, for controlling such ‘smart craft’, is drawing ever closer to becoming a reality.

With Special thanks to Mark Dunn.

Copyright (c) 2006 Caryn Anscomb. All rights reserved.

SOURCES OF REFERENCE:

http://science.nasa.gov/headlines/y2001/ast01mar_1.htm

http://ipt.arc.nasa.gov/Graphics/nanotechresearch.pdf

http://www.newscientist.com/article.ns?id=dn4484

http://www.darpa.mil/dso/thrust/matdev/chap/html/proj_sarcos.html