"Genius Materials" on the ISS   
       
   Nov. 27, 2013:  If you have a smartphone, take it out and run your fingers   
   along the glass surface.  It's cool to the touch, incredibly thin and strong,   
   and almost impervious to scratching.  You're now in contact with a "smart   
   material."   
       
   Smart materials don't occur naturally.  Instead, they are designed by human   
   engineers working at the molecular level to produce substances made-to-order   
   for futuristic applications. The Corning Gorilla Glass that overlays the   
   displays of many smartphones is a great example. It gets it toughness, in   
   part, from "fat" potassium ions stuffed into the empty spaces between   
   old-fashioned glass molecules. When the molten glass cools during   
   manufacturing, dense-packed molecules solidify into a transparent armor that   
   gives Gorilla Glass its extraordinary properties.   
       
   https://www.youtube.com/watch?v=GgH8vmsvdxs   
       
   With proper coaxing, molecules in microgravity can assemble themselves into   
   forms with surprising properties. A new ScienceCast video explores the   
   possibilities. Play it   
       
   Around the world, designers are working on other smart materials such as   
   alloys that can change shape on demand, plastics that heal themselves when   
   ruptured, and fluids that obey magnetic commands to flow or stiffen under   
   computer control.   
       
   "One of the great challenges in creating a smart material is arranging the   
   molecules," says Eric Furst of the University of Delaware.  "They're so small!"   
       
   Furst wants to create a new class of materials, beyond smart. "We need 'genius   
   materials'--materials that arrange themselves," he says.   
       
   Auroras Underfoot (signup)The research to accomplish this is already underway   
   on the International Space Station.   
       
   Furst is the principal investigator of an experiment called InSPACE-3.  In the   
   microgravity of Earth orbit, vials of fluid mixed with very small 'colloidal'   
   particles (about a millionth of a meter in diameter) are exposed to magnetic   
   fields. Magnetism is switched on and off again very rapidly. This jostles the   
   particles, causing them to bump together and self-assemble into microscopic   
   structures that currently no supercomputer can predict.   
       
   "Astronauts enjoy watching this process in action through microscopes," says   
   Furst.  "Because the samples are backlit by a green lamp, they sometimes call   
   it the 'green blob experiment.'"   
       
   Furst recently won an award from the American Astronautical Society for his   
   work on InSPACE-3.   
       
   http://tinyurl.com/k4e6dtu   
       
   A Quicktime movie (31 MB) of the InSPACE-3 "green blob" experiment. Play   
   it"I'm excited," he continues. "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."   
       
   Recently, observers have seen the colloidal particles forming long fibrous   
   chains. Furst speculates that these could lead to materials that conduct heat   
   or electricity in one direction only.  The experiment has also yielded   
   crystalline structures that the team is just beginning to investigate.   
       
   The fluids underlying these tests are themselves very smart.  They are called   
   magnetorheological or "MR" fluids because they harden or change shape when   
   they feel a magnetic field.   
       
   If you own a sports car or a Cadillac, you might have MR fluids in your shock   
   absorbers. The stiffness of magnetic shocks can be electronically adjusted   
   thousands of times per second, providing a remarkably smooth ride. Similar but   
   more powerful devices have been installed at Japan's National Museum of   
   Emerging Science and China's Dong Ting Lake Bridge. They're there to   
   counteract vibrations caused by earthquakes and gusts of wind. Some   
   researchers have speculated that MR fluids might one day flow through the   
   veins of robots, moving artificial joints and limbs in lifelike fashion.   
       
   Furst and colleagues are using these fluids as a laboratory for studying   
   self-assembly. MR fluids are, by definition, responsive to the magnetic   
   nudging that sets self-assembly in motion.  Furthermore, in space the   
   particles don't sediment out due to gravity. "We can study the full 3D   
   evolution of the material," he adds.   
       
   Varying the shape of the colloidal particles, the cadence of magnetic   
   toggling, the temperature of the fluid and other factors will allow   
   researchers and astronauts to further explore the frontiers of self-assembly.   
       
   Touch the surface of your smartphone again.  Maybe that's just the beginning.   
       
   Credits:   
   Author: Dr. Tony Phillips | Production editor: Dr. Tony Phillips | Credit:   
   Science@NASA   
       
   More information:   
       
   InSpace-3 -- Investigating the Structure of Paramagnetic Aggregates from   
   Colloidal Emulsions - 3 (InSPACE-3)   
       
   Robot Blood -- Science@NASA   
       
       
   Regards,   
       
   Roger   
      
   --- D'Bridge 3.96   
    * Origin: NCS BBS - Houma, LoUiSiAna (1:3828/7)