Acidithiobacillus ferrooxidans is a gram-negative bacterium that lives, in the natural world, in iron sulfide (aka “pyrite,” aka “fool’s gold) deposits, where it eats iron and sulfur and excretes sulfuric acid.

Now, a team of graduates, undergraduates, and post-docs at New York’s Columbia and Cooper Union universities is working to develop a genetically-modified strain of A. ferrooxidans that can be used in place of toxic bulk chemical reagents to selectively etch copper to make printed circuit boards:

By genetically altering the bacteria, we intend to install a light sensitive mechanism which will enable us to etch copper in a desired pattern, leaving a finished circuit board. Once a blank printed circuit board is placed in a thin layer of solid media, the bacteria will be applied onto the surface of the media and light will be focused on it in a desired pattern. The light sensitive mechanism in ferrooxidans would activate and self-destruct in the pathway of the light. In the end, the circuit board will be “etched” by the bacteria everywhere but the illuminated spots, leaving the desired pattern behind on the circuit board.

The combined Columbia-Cooper Union team are entering this project in the 2012 iGem Synthetic Biology competition. Check out the link, below, for more details, and come see them in person, if you can, at World Maker Faire 2012.

IGEM 2012 Team Information – Columbia-Cooper-NYC

Maker Faire Project Profile

PCB Using Controlled Etching by Bacteria, A. ferrooxidans

The Columbia-Cooper iGEM team is working with Acidithiobacillus ferrooxidans to create a light-controlled printed circuit board manufacturing process. This bacteria's metabolism relies on its ability to oxidize iron; the iron can then be used to oxidize, and in turn solubilize, copper. By genetically altering the bacteria, we intend to install a light sensitive mechanism which will enable us to etch copper in a desired pattern, leaving a finished circuit board.

• Project Website
• Video
• Maker Faire Page