Incredibly thin, flexible, strong and electrically conductive, graphene has the potential to revolutionize electronics and materials. One of the main hurdles though is that it's tricky to manufacture on large scales. Now researchers at the University of Rochester have recruited bacteria to make the stuff, which is cheaper and faster than current methods and doesn't require harsh chemicals.

Graphene production has come a long way since researchers first used sticky tape to peel single-atom-thick layers off of lumps of graphite. Now it's often made by chemical vapor deposition, or by shredding graphite into graphene oxide then chemically reducing it. Both of those methods generally require the use of harsh chemicals though, leading scientists to find softer alternatives.

For the new study, the team found that a bacteria called Shewanella worked well as one such alternative. They first created graphene oxide from graphite, then mixed it in a vial with the bacteria and left it overnight. Given enough time, the bugs successfully reduced it into a more useful graphene material.

"Graphene oxide is easy to produce, but it is not very conductive due to all of the oxygen groups in it," says Anne Meyer, lead researcher on the study. "The bacteria remove most of the oxygen groups, which turns it into a conductive material."

From left: A vial of graphite, a vial of graphene oxide and Shewanella bacteria, a vial of graphene produced by the bacteria, and a vial of graphene produced chemically Delft University of Technology / Benjamin Lehner

Not only was the bacteria cleaner than using chemical reduction methods, but the resulting graphene performed better than that produced through other means. The researchers also claim the bacteria-created graphene was thinner and more stable, and could be stored for longer.

The team says the new technique could be used to make graphene for electronics or conductive inks. These could make for electric circuits that can be printed onto materials like paper or fabric. The researchers even got creative with their experiments.

"Our bacterially produced graphene material will lead to far better suitability for product development," says Meyer. "We were even able to develop a technique of 'bacterial lithography' to create graphene materials that were only conductive on one side, which can lead to the development of new, advanced nanocomposite materials."

The research was published in the journal ChemOpen.

Source: University of Rochester