Bacterial graphene solar: a new generation of solar cells produced with the help of bacteria.
A good part of the new graphene study is its unusual manufacturing method. This graphene has unique electronic properties due to its nanoscale folds. These wrinkles are caused by the addition of bacteria to the manufacturing process.
Yes, bacteria -- one of the oldest living things on earth -- have been used to tailor new nanomaterials (graphene was discovered in 2004). Folding on graphene surfaces is not a novel approach. But conventional methods, such as stretching the sheet layer and causing it to suddenly fold back, are effective, but do not yield particularly accurate folds.
The team for the new project was created by the university of Illinois at Chicago. Their idea was to create precise folds by arranging arrays of bacteria directly into graphene.
Under a microscope, bacillus subtilis looks like a mini sausage. The team arranged them like sausage strings and placed them in a single layer of graphene with an electric field. Next, they put graphene/bacteria into a vacuum. Water is drawn from bacteria in a vacuum, forcing them to shrink. Because graphene is so flexible, it reconfigures as rows of bacteria shrink, resulting in precisely aligned nanofolds.
"Because carbon nanotubes are created in a vacuum, the resulting mix is different from graphene in nature," said Vikas Berry, the team's leader. The electron clouds that fold around the carbon atoms create a "V"... This can extend the dipole moment of the electron band gap, but planar graphene does not have this property.
According to Berry's description, this uniform arrangement creates a difference in the electric field, making the transverse current less than the longitudinal current. The team's next goal is to improve and cut the folds more precisely, to achieve the goal of about two nanometres (small in the world) apart.
You can be in the Nano in the magazine "Confined, Oriented, and Electrically Anisotropic Graphene Wrinkles on Bacteria." to get more details. Anisotropy refers to the different properties of materials in different directions The results showed that bioinduced graphene folds with controllable, directional and electron anisotropy could be used in electron, bioelectromechanical and strain modes.