Intricate patterns formed by granular materials under the influence of electrostatic fields have scientists at the U.S. Department of Energys Argonne National Laboratory dreaming of new ways to create smaller structures for nanotechnologies. With a combination of electric fields and fluid mixtures, researchers Igor Aronson, Maksim Sapozhnikov, Yuri Tolmachev and Wai Kwok can cause tiny spheres of bronze and other metals to self-assemble into crystalline patterns, honeycombs, pulsating rings and bizarre two-lobed structures that whirl like tiny propellers. Such self-assembling behavior could be exploited to create the next generation nanostructures or tiny micromechanical devices. Their work has been reported in the Physical Review Letters (Phys. Rev. Lett. 90, 114301, 2003).
The research started about four years ago, when Igor Aronson was studying the surprisingly regular patterns formed when granular materials like sand are vibrated, seeking clues to the dynamics of such substances. "Despite about a thousand years of practical experience, we still dont completely understand granular materials," Aronson said. "They can display the properties of solids or liquids, and behaviors that defy conventional physics."
Aronson and colleagues investigated the reaction of a very fine granular material in an electrostatic field. They placed a quarter-teaspoon of 100-micron bronze spheres between two transparent sheets coated with conducting material. Under high voltage, each bronze sphere acquires a charge from the bottom plate and is attracted to the upper sheet. The spheres reverse charge when they hit the upper sheet and are repelled back toward the lower sheet. As the process repeats 40 times per second, the bronze particles form a shimmering "gas" between the two plates. Groups of particles, responding to the electric field from the plates and from each other, tend to cluster together and coalesce into large, random groups.
Donna Jones Pelkie | EurekAlert!
Light-driven atomic rotations excite magnetic waves
24.10.2016 | Max-Planck-Institut für Struktur und Dynamik der Materie
Move over, lasers: Scientists can now create holograms from neutrons, too
21.10.2016 | National Institute of Standards and Technology (NIST)
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
24.10.2016 | Earth Sciences
24.10.2016 | Life Sciences
24.10.2016 | Physics and Astronomy