It's a small, small, small world
(Page 2 of 2)
Able to leap a 20-foot wall in a single bound! Stronger than a speeding bullet! Able to sense danger in the air! No, it isn't Superman, but it could be the soldier of tomorrow.Skip to next paragraph
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Researchers at the Massachusetts Institute of Technology in Cambridge, Mass., using nanotechnology, are working to create a "super uniform" for soldiers.
The new duds will enable a soldier to do everything listed above, yet weigh no more than paper, yard for yard (not counting boots, of course). They will be soft and flexible but able to harden into an intimidating forearm karate glove.
To develop the "cloth" that will be sewn into uniforms, MIT recently opened the Institute for Soldier Nanotechnologies. Here, physicists, chemists, and material scientists delve into a tiny world.
The lab has three main jobs, says Paula Hammond, a professor of chemical engineering. First, the fabric has to be comfortable to wear, she says. But it has to become stiffer under certain conditions to protect its wearer.
Second, it has to be lightweight. The typical United States soldier carries from 125 to 145 pounds of equipment. Researchers hope to trim nearly 100 pounds from that, to 45 pounds..
Third, the uniform should also be able to detect a change in the environment, such as light, temperature, or air quality. If some change poses a danger, a soldier's uniform would let him or her know. "We want clothing that will protect them against potential biological or chemical agents," Professor Hammond says.
To create such a "smart" jacket, scientists might insert tiny sensors into the fabric. When the sensors detect cold temperatures, the uniform might respond by becoming more insulating. When it gets warm, the uniform might become more "breathable," to cool off the soldier. Smart materials can also be designed to respond to hazardous materials, such as nerve gas or biological agents.
Creating the sensors is just the first step. Connect the sensors to a microprocessor, and you'll get a pair of very intelligent pants.
What about leaping that 20-foot wall?
"There is a hope that we can increase the soldiers' capabilities by storing energy while they are walking," Hammond says. "This involves a lot of physics."
Every time you take a step, you release energy when your foot strikes the ground. The energy is released as sound (footsteps) or goes into making impressions in the ground (footprints). Hammond's group hopes to capture some of that wasted energy in a special sock or shoe made from a material that stores energy somehow.
"We aren't sure where this is going yet," Hammond says. The "jump" may be only one good thrust. A soldier might have to walk another 20 miles before he or she has stored enough energy for another leap. But one good jump might save him.
Physicists, electrical engineers, and material scientists are working together to develop the uniforms. Hammond expects wearable results within five years.
Eventually, this research will affect the clothes other people wear as well fire fighters, police officers, and other emergency workers, for example.
"This is a very exciting world," Hammond says. "On the nano level, you can change a material so that it will do just about anything."
It may be the world's smallest harp, but it doesn't play music. It's an example of a nano-electrical-mechanical device.
Like a real harp, it has "strings." The strings are 50 nanometers (nm) in diameter. That's 50 billionths of a meter, or about 150 atoms thick! They range in length from 1,000 to 8,000 nm. The whole "harp" is the size of a red-blood cell.
Each "string," made from silicon, can vibrate. If one could hear them, each would make a different sound, says Harold Craighead. He's a professor of applied and engineering physics at Cornell University in Ithaca, N.Y.
"We carved the harp from the same sort of material that computer chips are made from silicon wafers," Professor Craighead says. The carving tool was a beam of electrons.
The strings are "plucked" with a laser beam. By studying how each string behaves and how long it vibrates, scientists find out how materials behave at such a tiny scale.
The research may lead to motion sensors that can detect the movement of a single molecule or bacteria. It could also lead to 3-D displays on hand-held computer games. "Children today should expect to see such devices before they grow up," Craighead says.
micron (MY-cron): 1/10,000th of a millimeter, or one-millionth of a meter. The width of a human hair be anywhere from about 20 to almost 200 microns wide.
nanometer (NA-no-mee-ter): One-billionth of a meter.
molecule (MOLL-uh-cyool): A molecule is the smallest particle of an element or compound that can still retain the characteristics of that element of compound. Example: A molecule of water is two hydrogen atoms bonded to one atom of oxygen.