Designer Materials Possible With Designer Electrons
Remarkable new 'designer materials' are being created by Stanford University scientists, working at the Department of Energy's SLAC National Accelerator Laboratory.
(Designer Materials Possible With Designer Electrons)
"The behavior of electrons in materials is at the heart of essentially all of today's technologies," said Hari Manoharan, associate professor of physics at Stanford and a member of SLAC's Stanford Institute for Materials and Energy Science, who led the research. "We're now able to tune the fundamental properties of electrons so they behave in ways rarely seen in ordinary materials."
Their first examples, reported Wednesday in Nature, were handcrafted, honeycomb-shaped structures inspired by graphene, a pure form of carbon that has been widely heralded for its potential in future electronics.
To make the structure, which Manoharan calls molecular graphene, the scientists use a scanning tunneling microscope to place individual carbon monoxide molecules on a perfectly smooth copper surface. The carbon monoxide repels the free-flowing electrons on the copper surface and forces them into a honeycomb pattern, where they behave like graphene electrons.
Precisely positioned carbon monoxide molecules (black) guide electrons (yellow-orange) into a nearly perfect honeycomb pattern called molecular graphene.
To tune the electrons' properties, the researchers repositioned the carbon monoxide molecules on the surface; this changed the symmetry of the electron flow. In some configurations, electrons acted as if they had been exposed to a magnetic or electric field. In others, researchers were able to finely tune the density of electrons on the surface by introducing defects or impurities. By writing complex patterns that mimicked changes in carbon-carbon bond lengths and strengths in graphene, the researchers were able to restore the electrons' mass in small, selected areas.
"One of the wildest things we did was to make the electrons think they are in a huge magnetic field when, in fact, no real field had been applied," Manoharan said.
Science fiction fans are excited by this development because it could lead to science fiction materials that previously existed only in novels.
I'm sure readers have their own favorite sfnal materials; here are a few of mine:
Fanmetal
High tensile strength material; used in collapsible structures (from Frank Herbert's 1965 novel Dune).
Glassite
A strong, transparent material (from the 1930 novel Brigands of the Moon by Ray Cummings.
Helio-Beryllium
Unusual alloy combines a metal and a gas (from Robert H. Wilson's 1931 story Out Around Rigel)
Steelonium
Steel that did not rust or corrode (from Hugo Gernsback's 1911 novel Ralph 124c 41 +).
Technovelgy (that's tech-novel-gee!)
is devoted to the creative science inventions and ideas of sf authors. Look for
the Invention Category that interests
you, the Glossary, the Invention
Timeline, or see what's New.
A System To Defeat AI Face Recognition
'...points and patches of light... sliding all over their faces in a programmed manner that had been designed to foil facial recognition systems.'
Smart TVs Are Listening!
'You had to live -- did live, from habit that became instinct -- in the assumption that every sound you made was overheard...'