Julia Greer, assistant professor of materials science and mechanics at Caltech, is part of a team of researchers who have developed the world’s lightest solid material, with a density of just 0.9 milligrams per cubic centimeter, or approximately 100 times lighter than Styrofoam™. Though the material is ultra-low in density, it has incredible strength and absorbs energy well, making it potentially useful for applications ranging from battery electrodes to protective shielding.
They shrink when you heat 'em. Most materials expand when heated, but a few contract. Now engineers at the California Institute of Technology (Caltech) have figured out how one of these curious materials, scandium trifluoride (ScF3), does the trick—a finding, they say, that will lead to a deeper understanding of all kinds of materials.
For the first time, researchers at Caltech, in collaboration with a team from the University of Vienna, have managed to cool a miniature mechanical object to its lowest possible energy state using laser light. The achievement paves the way for the development of exquisitely sensitive detectors as well as for quantum experiments that scientists have long dreamed of conducting.
In the last couple of years, researchers have observed that water spontaneously flows into extremely small tubes of graphite or graphene, called carbon nanotubes. However, no one has managed to explain why. Now, using a novel method to calculate the dynamics of water molecules, Caltech researchers believe they have solved the mystery. It turns out that entropy, a measurement of disorder, has been the missing key.
Caltech scientists have concocted a recipe for a thermoelectric material—one that converts heat energy into electricity—that might be able to operate off nothing more than the heat of a car's exhaust. In a paper published in Nature this month, G. Jeffrey Snyder and his colleagues reported on a compound that shows high efficiency in a temperature range of around 260 to 1160 degrees Fahrenheit. In other words, the heat escaping out your car's tailpipe could be used to help power its electrical components.
Caltech scientists have conducted experiments confirming which of three possible mechanisms is responsible for the spontaneous formation of 3-D pillar arrays in nanofilms. These protrusions appear suddenly when the surface of a molten nanofilm is exposed to an extreme temperature gradient and self-organize into hexagonal, lamellar, square, or spiral patterns.
Stronger than steel or titanium—and just as tough—metallic glass is an ideal material for everything from cell-phone cases to aircraft parts. Now, researchers at the California Institute of Technology (Caltech) have developed a new technique that allows them to make metallic-glass parts utilizing the same inexpensive processes used to produce plastic parts. With this new method, they can heat a piece of metallic glass at a rate of a million degrees per second and then mold it into any shape in just a few milliseconds.
A new class of artificial materials called metamaterials may one day be used to create ultrapowerful microscopes, advanced sensors, improved solar cells, computers that use light instead of electronic signals to process information, and even an invisibility cloak. In a Perspectives piece in this week's issue of the journal Science, Caltech's Harry Atwater and Purdue University colleague Alexandra Boltasseva describe advances in a particular subtype of these materials—plasmonic metamaterials.
Using a common metal most famously found in self-cleaning ovens, Sossina Haile hopes to change our energy future. The metal is cerium oxide—or ceria—and it is the centerpiece of a promising new technology developed by Haile and her colleagues that concentrates solar energy and uses it to efficiently convert carbon dioxide and water into fuels.
A Caltech-led team has created a palladium-based metallic glass that has a combination of strength and toughness at a level not previously been seen in any other material. The study demonstrates for the first time that the metallic glasses have the capacity to become the toughest and strongest materials ever known, the researchers say.