Materials engineers and chemists at NanoSonic, Inc., have developed a way to produce lightweight electrically conductive textiles that won't break or disintegrate when you wash or stretch them. This makes the textiles perfect for use in sensor-laden "smart clothes." An important component is the company's trademarked metal rubber, a substance that has the elasticity of rubber and ability of steel to conduct electricity/NanoSonic's metal rubber and e-textiles could find use in protective clothing; flexible antennae and circuits; flexible displays; electromagnetic shielding; biomedical sensors and health monitoring; and applications in outer space.
HOW IT'S MADE: Instead of just mixing different materials together, like in a blender, or weaving metal wire components into fabrics, NanoSonic's manufacturing technique is a bit like "growing" textiles in a makeshift washing machine. It's called "electrostatic self-assembly." By dipping the base material into baths of alternating electrons and protons, those nanoparticles with opposite charges attract and stick to each other like Velcro. So many different properties can be linked together without the material falling apart when it is washed or stretched. Each dip adds one layer. The e-textiles are lower in weight, with lower manufacturing costs and few byproducts, plus they can withstand repeated washings without falling apart.
EXAMPLES: In combat conditions, a U.S. solder clothed in layers of garments made from e-textiles could wear sensors close to the skin that monitor blood pressure, body temperature, and heart rate. Another layer could be integrated into the Kevlar vest to register impact from a bullet or shrapnel. And sensors in an outer garment could "sniff" the air for toxic agents of chemical or biological warfare. It might also be possible to make a thicker but lightweight conductive fabric for electric power workers that would not limit their range of motion, but would reduce the effects of electric power line radiation.
ABOUT SELF-ASSEMBLY: There are two basic ways to manipulate matter. On the large scale, we pick things up with our hands and physically put them together. Nature uses self-assembly, assembling its structures molecule by tiny molecule. Spread out in a liquid, the miniature parts jostle about and come together in random configurations, gradually matching up through trial and error according to shape and electrical charges. It's as if you shook a box holding the pieces of a jigsaw puzzle, and looked in to find the puzzle had assembled itself. Yet biological systems, as well as several inorganic physical systems, exhibit self-assembling or self-ordering behavior all the time.
