American researchers have produced electricity from the union of a humble button mushroom and photosynthetic cyanobacteria.
Led by Manu Mannoor and Sudeep Joshi, a team of scientists from the Steven Institute of Technology (SIT) in New Jersey 3D printed a branched pattern of electronic ink containing graphene nanoribbons onto the cap of the living mushroom. They then printed bioink containing cyanobacteria onto the same cap in a spiral pattern intersecting the electronic ink at multiple points.
These intersections allowed electrons to transfer through the outer membranes of the bacteria into the conductive network of graphene nanoribbons. As cyanobacteria produce energy using photosynthesis, this process could only be activated when a light was shone on the mushroom. The setup was able to produce a current of 65 nano-amps.
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Previous efforts to use this mechanism on artificial surfaces failed because the cyanobacteria did not have access to the nutrition it needed. This space was filled by the button mushroom. It’s porous structure also provides the necessary water channels.
While the researchers acknowledge that this amount of current doesn’t amount to much, they argue that an array of these ‘bionic mushrooms’ could generate enough electricity to light up an LED bulb. They are currently working on ways to generate even more electricity.
However, this study, which was published in the journal Nano Letters, is not exclusively focused on electric fungi. The team at SIT believe this same approach could be used to organise other species for several uses, such as the production of electricity or bioluminescence.
“The biological microworld is classified into several kingdoms, wherein bacterial and fungal kingdoms reap mutual benefits by exhibiting significant mutualistic symbiosis” says the study. The researchers added that, “engineering a multidimensional integration among different microbiological kingdoms can harness advantage by exploring the existence of rational bionic symbiosis.”