ScienceShot: Earplugs in Space

Staff Writer

Cross a rubber band with a puddle of honey, and you have some sense of what a "viscoelastic" material is. Like a rubber band, it's elastic: stretch it, and it returns to its original shape. But like honey, it's viscous, which means it's also malleable. What you end up with is a material that, when squeezed or stretched, returns to its original shape—but slowly. Think foam earplugs. Sounds cool, but there's one limitation: One of the most common viscoelastics only works in a limited temperature range, -55° to 300°C. Too hot and it melts. Too cold and it becomes brittle. Now researchers in Japan report online today in Science that they've made a random network of long, interconnected carbon nanotubes (image) that remains viscoelastic between -19° and 1000°C. The surprising stability, they say, is due in part to the ability of the tiny carbon tubes to handle strain by flattening out and then recovering their original shape. The wide temperature range could make them ideal materials for use in extreme environments, such as in rubbery tires on space vehicles. 

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Posted in Physics