November 27, 2013
Creating ‘Genius Material’ Aboard The ISS
[ Watch The Video: ScienceCast Genius Materials On The ISS ]
Lee Rannals for redOrbit.com - Your Universe OnlineThe glass on a smartphone is considered to be a 'smart material,' but scientists are working to create 'genius materials' in an experiment aboard the International Space Station (ISS).
Corning Gorilla Glass is the type of glass used on smartphones, making the devices resistant to abrasions and low drops. The glass’ toughness is due in part to “fat” potassium ions stuffed into the empty spaces between old-fashioned glass molecules. When molten glass cools during manufacturing, densely-packed molecules solidify into a transparent armor that gives the glass its properties.
"One of the great challenges in creating a smart material is arranging the molecules," explained Eric Furst, a chemical and biomolecular engineer at the University of Delaware. "We need 'genius materials' - materials that arrange themselves.”
Furst is the principal investigator of an experiment called InSPACE-3 aboard the ISS space station. While experimenting on the ISS, vials of fluid are mixed with very small colloidal particles and then are exposed to magnetic fields. The magnetism is switched on and off very rapidly, jostling around the particles and causing them to bump against one another and self-assemble into microscopic structures.
"Astronauts enjoy watching this process in action through microscopes. Because the samples are backlit by a green lamp, they sometimes call it the 'green blob experiment,'" said Furst. "Just by toggling a magnetic field, we're learning how to take any kind of microscopic building blocks and get them to spontaneously form interesting structures."
The observers have seen the colloidal particles forming long fibrous changes, which Furst speculates could lead to materials that conduct heat or electricity in one direction only. InSPACE-3 has also yielded crystalline structures that the team is just now starting to investigate.
Fluids underlying the tests are called magnetorheological, or 'MR,' because they harden or change shape when they feel a magnetic field. This type of fluid is found in sports cars’ shock absorbers, helping to provide a remarkably smooth ride.
Scientists believe that MR fluids could one day flow through the veins of robots, helping to move artificial joints and limbs in a lifelike fashion. Devices have been installed using MR fluids at Japan's National Museum of Emerging Science and China's Dong Ting Lake Bridge to help counteract vibrations caused by earthquakes and gusts of wind.
The researchers in the InSPACE-3 experiment are able to study the full 3D evolution of the material due to the microgravity conditions.