Nobel Worthy: Best Graphene Close-Ups
Sorry diamond lovers, but graphene is the most awesome form of carbon out there. Evidence: Andre Geim and Konstantin Novoselov, the two scientists who isolated one-atom-thick sheets of the stuff in 2004, won the Nobel Prize this morning -- netting themselves a pot of 10 million Swedish kroner (about $1.49 million).
Despite its razor-thin makeup, graphene is one of the strongest, lightest and most conductive materials known to humankind. It’s also 97.3 percent transparent, but looks really cool under powerful microscopes. We’ve corralled some of the best shots here, with a bonus video of graphene being punished by an electron beam.
Geim and Novoselov persisted, however, and figured out how to isolate it using objects common to any office: Scotch tape and graphite, which is found in pencil leads.
At the top-right of this image is a 10-micron-wide, 30-layer-thick slice of graphene sheets.
Image: Science
To prove in 2004 that they’d isolated one using the tape-and-graphite method, Keim and Novoselov peeled off a single flake of graphene and stuck it onto silicon dioxide (the same stuff used to make semiconductors in electronics). Similar to how a sheen of oil becomes visible in a rainbow of colors on water, the combination of graphene on oxidized silicon revealed the flake in an electron microscope.
Image: Science
In this video, Berkeley Lab scientists subject an unsuspecting sheet of graphene to the punishment of a powerful electron beam. The beam punched a hole in the graphene, causing individual carbon atoms to scramble for a spot to stick at the hole's edge.
Video/image: Lawrence Berkeley National Laboratory
Pounding the Graphene SkinsDespite its razor-thin makeup, graphene is one of the strongest, lightest and most conductive materials known to humankind. It’s also 97.3 percent transparent, but looks really cool under powerful microscopes. We’ve corralled some of the best shots here, with a bonus video of graphene being punished by an electron beam.
Mmmm... Graphene Cake
Theoretical physicist Philip Russell Wallace predicted graphene’s existence in 1947, but it wasn’t until the 1960s that scientists began looking for it in earnest. Forty years later, researchers practically wrote off isolating single-layer graphene. If the hexagonal layers didn’t roll up into buckeyballs or nanotubes, so the thinking went, they’d disintegrate entirely.Geim and Novoselov persisted, however, and figured out how to isolate it using objects common to any office: Scotch tape and graphite, which is found in pencil leads.
At the top-right of this image is a 10-micron-wide, 30-layer-thick slice of graphene sheets.
Image: Science
Between the Graphene Sheets
The problem with seeing a single sheet of graphene is that it’s practically invisible.To prove in 2004 that they’d isolated one using the tape-and-graphite method, Keim and Novoselov peeled off a single flake of graphene and stuck it onto silicon dioxide (the same stuff used to make semiconductors in electronics). Similar to how a sheen of oil becomes visible in a rainbow of colors on water, the combination of graphene on oxidized silicon revealed the flake in an electron microscope.
Image: Science
There's a Hole in My Graphene
Graphene may be the strongest carbon-based material, period, but it can’t stop a beam of electrons.In this video, Berkeley Lab scientists subject an unsuspecting sheet of graphene to the punishment of a powerful electron beam. The beam punched a hole in the graphene, causing individual carbon atoms to scramble for a spot to stick at the hole's edge.
Video/image: Lawrence Berkeley National Laboratory
Graphene drum? Check. Laser microphone? Check. Rock on.
In a 2007 test of graphene’s ability to resonate, researchers at Pomona College in California and Cornell University in New York stretched a 2-nanometer-wide ribbon of graphene over a silicon dioxide trench, then used an electrode to vibrate the sheet.
Image: Science
Graphene Bubble
Graphene is made up of carbon arranged into chicken-wire-like hexagonal rings, yet the bonds between any carbon atoms can stretch up to 20 percent. The arrangement may seem innocuous, yet it paves the way for quantum mechanical weirdness to manifest itself.
Case in point: When scientists sandwiched graphene onto platinum, then popped out a microscopic bubble, electrons in the graphene sheet behaved as if they were being punished by a magnetic field stronger than any ever produced in a laboratory. No magnetic field was in sight, so the effect was called (naturally) pseudo-magnetism.
Image: Lawrence Berkeley National Laboratory
Ribbons 'O Graphene
To say graphene conducts electricity well is a gross understatement. The electrons buzzing around graphene’s carbon atoms are unusually free to roam and behave more like massless pieces of light called photons. This allows graphene to be used like a high-performance transistor capable of operating at speeds 100 to 1,000 times faster than silicon-based transistors.
Trouble is, graphene moves electrons around a little too well. The threshold between graphene’s on/off state is exceedingly small, causing it to conduct electricity even in an “off” state. By growing micron-thin ribbons of graphene (above) instead of full sheets, however, chemists like Hongjie Dai at Stanford University have raised that threshold more than 10,000 times. Further improvements could lead to high-speed graphene-powered electronics.
Image: Hongjie Dai/Stanford University
Graphene Transistor
Capitalizing on graphene’s electrical awesomeness, HRL Laboratories (owned by Boeing and General Motors) built the world’s first functional radio frequency (RF) transistor using graphene in 2008. The tiny device, known as an RF field-effect transistor, can pick up radio frequencies while hardly gobbling any electrical power.
The company has since scaled up a full-size chip of the transistors, but alleged practical uses in imaging and communications remain to be seen.
Image: HRL Laboratories
By Dave Mosher
October 5, 2010
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