As well as the use of microorganisms, also key to the technology is graphene (a single later of atoms that is very strong, flexible and which boasts excellent conductive properties). The manipulation of graphene involves working in the nanoscale. One thing that has held back the application of graphene for industrial-scale processes is the ability to mass produce the material.
Researchers based at the University of Rochester together with scientists from the Delft University of Technology have outlined a framework to produce graphene to scale – with the help of microbes. The two teams have described how it is possible to produce graphene materials by mixing oxidized graphite with bacteria. The novel method is said to be low cost, relatively fast, and environmentally sustainable.
The process generates graphene from an extraction of graphite, in this case by a type of exfoliation. The researchers succeeded in shedding layers of material to produce graphene oxide. This was then added to a culture of the bacterium Shewanella (a genus of marine bacteria found in extreme habitats where the temperature is very low and the pressure is very high.). The mix of the bacteria and precursor materials only need to be in contact for twelve hours, by which time the bacteria can reduce the graphene oxide to graphene by removing oxygen groups.
The new process not only produces graphene, the researchers state that the type of graphene produced with the aid of bacteria is thinner and more stable than graphene produced chemically. This will make this type of graphene useful for technologies like field-effect transistor biosensors (used for assessing biomarkers for conditions like diabetes) and conducting ink, which can be used to fabricate the electrical circuits required for computer keyboards or circuit boards.
The research has been published in the journal Chemistry Open, with the research paper titled “Creation of Conductive Graphene Materials by Bacterial Reduction Using Shewanella Oneidensis.”