A team of researchers at the Stevens Institute of Technology has developed bionic mushrooms patterned with energy-producing cyanobacterial colonies and an electrode network.
An electrode network and cyanobacteria were 3D printed on a mushroom to generate bio-electricity. Image credit: Joshi et al, doi: 10.1021/acs.nanolett.8b02642.
Many examples of organisms that live closely together and interact with each other exist in nature. In some cases, this symbiotic relationship is mutually beneficial.
Stevens Institute of Technology researchers Manu Mannoor, Sudeep Joshi and Ellexis Cook set out to engineer an artificial symbiosis between button mushrooms and cyanobacteria.
“The covert biological microworld is comprised of a plethora of microorganisms which holds astounding, yet untapped functionalities, that offer enormous opportunities for exploration. These microbial species coexist, efficiently interact, and perform incredible tasks to maintain self-sustaining microbiota,” they explained.
“The biological microworld is classified into several kingdoms, wherein bacterial and fungal kingdoms reap mutual benefits by exhibiting significant mutualistic symbiosis.”
“Therein lies a greater engineering challenge in utilizing inherent capabilities and functionalities by selectively and controllably teaming-up different species from the biological microworld to realize functional bionic architectures toward innovative applications.”
“Therefore, a compelling scientific interest is to pay attention for inquisitive resources and techniques for tapping into the biological microworld for better cognizance leading toward novel opportunities.”
A bionic mushroom. Image credit: Joshi et al, doi: 10.1021/acs.nanolett.8b02642.
In the team’s scenario, the mushroom would provide shelter, moisture and nutrients, while cyanobacteria 3D-printed on the mushroom’s cap would supply energy by photosynthesis.
Graphene nanoribbons printed alongside the bacteria could capture electrons released by the microbes during photosynthesis, producing bio-electricity.
To make their bionic mushroom a reality, the researchers first 3D-printed an electronic ink containing graphene nanoribbons onto the cap of a living mushroom in a branched pattern.
They then printed a bio-ink containing cyanobacteria onto the cap in a spiral pattern, which intersected with the electronic ink at multiple points. At these sites, electrons could transfer through the outer membranes of the bacteria to the conductive network of graphene nanoribbons.
Shining a light on the mushroom activated cyanobacterial photosynthesis, generating a current of about 65 nA.
“Although this current is insufficient to power an electronic device, an array of bionic mushrooms could generate enough current to light up an LED,” the study authors said.
They are now working on ways to generate higher currents using this system.
“Our 3D-printing approach could be used to organize other bacterial species in complex arrangements to perform useful functions, such as bioluminescence,” they said.
The team’s work appears in the journal Nano Letters.
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Sudeep Joshi et al. Bacterial Nanobionics via 3D Printing. Nano Lett, published online November 7, 2018; doi: 10.1021/acs.nanolett.8b02642
