Jeff Brinker, a senior scientist at Sandia National Labs and a University of New Mexico professor, has discovered a new way of detecting mechanical, chemical, and thermal stress. Brinker uses intelligent nanostructures made from conjugated polymers that change from blue to red when changes in mechanical stress and temperature are introduced. The polymers change back to their original color when the stress and temperature changes are removed. The structures also change color in the presence of different solvents and chemicals. This colorful feat occurs at the nano level and involves linking monomers into polymers in an orderly fashion. "We have patents in progress on the general idea of self-assembly of nanocomposite materials," says Brinker. "We use surfactants both to direct the formation of the inorganic silica nanostructure and as monomers that become polymers in situ within the nanostructure to form the conjugated polymer," he explains. Conjugated polymers are typically similar to a bowl of entangled spaghetti, but Brinker found a way of organizing them. The materials are prepared by simple evaporation-driven processes like spin-coating, dip-coating, and ink-jet printing. Brinker notes the materials are easily integrated into devices, especially in thin-film form. By controlling interactions between the polymers, he effects the materials' electric and optical properties. The smart materials also serve mechanical functions such as protective coatings and permeation barriers. "Also, it is now recognized that to get better efficiency and function from conjugated polymers, it is necessary to organize them so as to control energy and electron transfer," says Brinker, adding that NASA, a sponsor of his work, is interested in thin films of the smart material for inflatable structures.
In honor of Earth Day, the National Security Agency has launched the STEM Recycling Challenge in Maryland schools to encourage kids to think about where the garbage they throw out every day actually goes. The agency has also introduced “Dunk,” a muscular blue cartoon recycling bin wearing shorts and sneakers.
A slew of announcements about new materials and design concepts for transportation have come out of several trade shows focusing on plastics, aircraft interiors, heavy trucks, and automotive engineering. A few more announcements have come independent of any trade shows, maybe just because it's spring.
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