Engineers at the Massachusetts Institute of Technology (MIT) have discovered a new method of producing electricity using tiny carbon particles that can generate a current just by interacting with the liquid around them, and this revolutionary approach might potentially be used to power micro- or nanoscale robots, according to a press release.
The liquid, described as an organic solvent in the journal Nature Communications, sucks electrons out of the particles, providing a current that could also be used to drive chemical processes. The researchers in fact demonstrated that this electric current could be utilized to drive an organic chemical reaction known as alcohol oxidation which is pretty important in the chemical industry.
The researchers have already begun developing small-scale robots that could one day be utilized as diagnostic or environmental sensors.
Back in 2010, lead author Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT, discovered that carbon nanotubes, hollow tubes comprised of a lattice of carbon atoms that are thinner than a human hair but stronger than steel, can generate "thermopower waves." That study led to this discovery, and now Strano and his students discovered another property of carbon nanotubes.
The researchers discovered that coating a portion of a nanotube with a Teflon-like polymer causes an imbalance that allows electrons to flow from the coated to the uncoated part of the tube, thus generating an electrical current. The researchers discovered that these electrons may be extracted by immersing the particles in a solvent that is "hungry for electrons."
To conduct the study and develop electricity-generating particles, the team ground up carbon nanotubes and shaped them into a sheet of paper-like material, which they then coated with a Teflon-like polymer on one side before cutting off microscopic particles of any form or size.
In total, they created particles that were 250 microns by 250 microns, and when these particles were immersed in an organic solvent, such as acetonitrile, the solvent stuck to the particles' surface and begun to take their electrons, in a way scavenging energy from its environment.
"The solvent takes electrons away, and the system tries to equilibrate by moving electrons," Strano explained. "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."
This way, the particles in their current form can create around 0.7 volts of electricity per particle. Strano said he aims to employ this type of energy generation to build polymers using only carbon dioxide as a starting material.