MIT scientists have developed a new electricity-generating material from carbon nanotubes.
These tiny carbon particles – made from crushed carbon nanotubes (blue) coated with a Teflon-like polymer (green) – interact with an organic solvent in which they’re floating, generating electricity by scavenging energy from its environment.
According to MIT professor Michael Strano, the technology is intriguing because all you have to do is flow a solvent through a bed of these particles: “This allows you to do electrochemistry, but with no wires.”
The electric current can also drive a reaction known as alcohol oxidation – an organic chemical reaction that’s important to the chemical industry.
Strano’s research on carbon nanotubes dates back to 2010, when he for the first time demonstrated that carbon nanotubes can generate ‘thermopower waves.’
That work led Strano and his students to uncover a related feature of carbon nanotubes.
They found that when part of a nanotube is coated with a Teflon-like polymer, it creates an asymmetry that makes it possible for electrons to flow from the coated to the uncoated part of the tube, generating an electrical current.
Those electrons can be drawn out by submerging the particles in a solvent that is hungry for electrons.
For this current study, Strano’s team created electricity-generating particles by grinding up carbon nanotubes and forming them into a sheet of paper-like material.
One side of each sheet was coated with a Teflon-like polymer, and the scientists then cut out small particles measuring 250 microns by 250 microns.
When these particles are submerged in an organic solvent such as acetonitrile, the solvent adheres to the uncoated surface of the particles and begins pulling electrons out of them.
“The solvent takes electrons away, and the system tries to equilibrate by moving electrons,” explains Strano.
“There’s no sophisticated battery chemistry inside. It’s just a particle and you put it into solvent and it starts generating an electric field.”
Though the present version of the particles are able to generate only about 0.7 volts of electricity per particle, Strano is confident that the approach can also be used to power micro- or nanoscale robots.
Image and content: Jose-Luis Olivares/MIT