MIT Engineers Discover a New Way to Generate Electricity

Tiny Particles Can Power Chemical Reactions

Carbon nanotubes, a new material made of carbon nanotubes, can produce electricity by absorbing energy from the environment.

Engineers at MIT have found a new method to generate electricity from tiny carbon particles. They interact with the liquid around them and create a current.

Researchers say that the organic solvent draws electrons from the particles and generates a current that could be used to drive chemical reactions or power micro- or small-scale robots.

Michael Strano, the Carbon P. Dubbs Professor in Chemical Engineering at MIT, says that “this mechanism is new” and generates energy in a completely new way. This technology is fascinating because you only need to flow a solvent through the bed of these particles. This allows for electrochemistry without the need to use wires.

Researchers have shown that electric current can drive an organic chemical reaction called alcohol oxidation. This is crucial in the chemical industry.

Strano is the senior writer of the paper. It appears in Nature Communications today. Albert Tianxiang Liu, an MIT graduate student, and Yuichiro Kunai, a former MIT researcher, are the lead authors. The study also includes Anton Cottrill (a graduate student), postdocs Amir Kaplan, Hyunah Kim, Ge Zhang (a graduate student), and Yannick Eatmon (a recent MIT graduate).

Unique properties

Strano’s work on carbon nanotubes, hollow tubes that are made up of lattice carbon atoms and possess unique electrical properties, led to the discovery. Strano showed that carbon nanotubes could generate a “thermopower wave” in 2010. This is a result of Strano’s 2010 research on carbon nanotubes. These hollow tubes are made of a lattice of carbon atoms and travel along the line creating an electric current.

Through this work, Strano and his students discovered a similar feature in carbon nanotubes. The researchers found that electrons can flow from one end of a nanotube coated with Teflon-like plastics, creating an asymmetry. This allows for an electric current to be generated. These electrons can be extracted by submerging them in a solvent hungry to absorb them.

To harness this unique capability, the researchers created electricity-generating particles by grinding carbon nanotubes and forming them into a paper-like material. The researchers coated one side of each sheet with a Teflon-like plastic, then cut small particles from the other. These can be any size or shape. They made particles measuring 250 x 250 mm.

These particles are submerged in an organic solvent, such as Acetonitrile. The solvent sticks to the surface of the particles and starts pulling electrons from them.

Strano states that the solvent removes electrons, and the system attempts to equilibrate through moving electrons. There is no battery chemistry. It is just a particle. When you place it in a solvent, it generates an electric field.

Jun Yao, an assistant professor of computer and electrical engineering at the University of Massachusetts at Amherst who wasn’t involved in the research, said that “this research cleverly shows how to extract the ubiquitous (and sometimes unnoticed!) electric energy stored within an electronic material for onsite electrochemical synthesis.” Adapting the generic method to other materials and applications for different synthetic systems is easy.

Particle power

Current versions of the particles can produce approximately 0.7 volts per particle. The researchers also demonstrated that hundreds of particles could be formed in a small tube. The “packed bed” reactor has enough energy to drive an alcohol oxidation reaction, where alcohol is converted into an aldehyde and a ketone. This reaction does not require electrochemistry as it would require too many external currents.

Zhang says the compactly packed bed reactor allows for more applications than large electrochemical reactors. “Particles can be made very small and don’t need wires to drive the electrochemical reaction,” Zhang says.

Strano plans to continue his work using this type of energy generation to make polymers with carbon dioxide as the starting material. He has also developed polymers that can be regenerated using carbon dioxide as a material in a related project. This was made possible by the use of solar energy. This work was inspired by carbon fixation. It is a series of chemical reactions plants use to create sugars from carbon dioxide.

This approach could be extended to power nano- and micro-scale robots in the long term. Already, Strano’s laboratory has begun building robots on that scale. These robots could be used one day as environmental or diagnostic sensors. He says that using energy from the environment to fuel these robots appeals to him.

He says, “It doesn’t mean you must put energy storage onboard.” This mechanism allows you to take energy from the environment, which is something we love.