Do you guess how you make a bespoke material with graphene-like properties? The bacteria can create brand new materials. For an example, if you use bacteria to print a substance resembling grapheme- the 2D material made of single atom layers of carbon-the end product have similar desirable properties. When placed on sheets of Graphene oxide, the bacteria can turn it into a reduced version of the compound, which shares many properties but it is easier to produce in large amounts. The bacteria do this by pulling oxygen atoms off the material as they metabolise. It is normally made by the help of powerful chemicals or extreme heat, but microbe-version is much cheaper and more environmentally friendly. The more you reduced, the closer it is to grapheme. It is very easy- it takes place at room temperature in sugar water.
The chemical process still seems to produce the best and excellence grapheme oxide, but the microorganisms could be very useful when it comes to fabricating precise small scale structures. That was 3D painting comes in.
By modifying a normal printer students showed that it is possible to bacteria onto a surface in precise lines just 1 millimeter wide. The gel solidifies when it touches calcium means that the bacteria stay in place. The idea is that you could eventually print a grapheme-oxide-reducing bacterium also known as Shewanella onedidensis, onto the material in definite patterns to tailor its properties like making some of areas as conductive and others not. It is easy to adapt 3D printers so they are able to print living cells. You need contracting properties of printing-on one hand being able to squeeze the liquid out of a nozzle, but also it being able to keep its shape afterwards, she says. The amount of growth medium the microorganisms needs to survive long enough to reduce the grapheme oxide would make it difficult to precisely print the solution without it spreading across the surface. If once technology is refined, as it could be possible to carve out tiny wires into the grapheme oxide surface while the rest remains non-conductive.