The publication ElectroIQ has an article on recent research coming out of Lawrence Berkeley National Laboratory that has shown that a three-point stretch of graphene creates nanobubbles in which the electrons segregate into quantized energy levels instead of occupying energy bands.
The research, which was originally published in the July 30th edition of the journal Science, has revealed that the electrons within the nanobubbles mimic the energy levels they would have if they were moving in circles in the presence of a strong magnetic field as high as 300 tesla.
According to Michael Crommie, professor of physics at UC Berkeley and a faculty researcher at LBNL, in the ElectroIQ article this discovery makes it possible to control how electrons move in graaphene and thereby manipulate the material’s electronic properties.
“By controlling where the electrons bunch up and at what energy, you could cause them to move more easily or less easily through graphene, in effect, controlling their conductivity, optical or microwave properties,” says Crommie in the article. “Control of electron movement is the most essential part of any electronic device."
As one might imagine, an experiment to stretch a piece of graphen was hardly planned. Instead this discovery was serendipitous after a UC Berkeley postdoctoral researcherand several students in Crommie’s lab grew graphene on a platinum crystal. Because the carbon atoms in graphene have a hexagonal pattern and the platinum has a triangular crystal structure they don’t line up and a strain pattern is created as though it were being pulled from three different directions.
While the findings may have been serendipitous, the results were predicted in carbon nanotubes as far back as 1997.
Now we can start using the term “straintronics” which involves, according to Crommie, “…the idea of using mechanical deformations in graphene to engineer its behavior for different electronic device applications."
Dexter Johnson is a contributing editor at IEEE Spectrum, with a focus on nanotechnology.