This Computer Has Been Running For A Year On Nothing But Algae
By Mikelle Leow, 17 May 2022
Image via Paolo Bombelli / University of Cambridge
Straight out of a cyberpunk film, this microcomputer can function without being plugged into a power outlet or being fueled with batteries. Instead, it is driven by self-sustaining algae.
Engineers at the University of Cambridge were looking for a way to keep Internet-of-Things electronics like smart washing machines, vehicles, coffee machines, home security systems, and the ilk running independently. A lot of machines in this category—such as autonomous farming equipment and environmental sensors—are far away from a power grid, so they knew they had to adopt a source that generates its own energy.
Solar cells have been a thing of fascination lately, but those require sunlight to keep computers going. Then, there are the more enigmatic “living” power sources, such as bioluminescent bacteria, but like all living beings, they’ll need to be sustained with food.
The researchers’ solution? A common blue-green algae species, called Synechocystis, that naturally creates its own food and energy through photosynthesis, enabling it to function in a remote area without being fed. And although photosynthesis happens in the presence of sunlight, this species seems to be able to generate electricity even in the dark because it continues to process its food at night.
Image via Paolo Bombelli / University of Cambridge
The team packed the near-neon algae into a structure the size of a AA battery, and then used it to power an ARM Cortex-M0+ chip in a microprocessor.
They then left the microcomputer on a windowsill, where it powered through a six-month test and continued running for six months after.
“Our photosynthetic device doesn’t run down the way a battery does because it’s continually using light as the energy source,” explains Christopher Howe, one of the study’s co-authors. The team published its findings in the Energy & Environmental Science journal.
Co-author Paolo Bombelli concludes: “We were impressed by how consistently the system worked over a long period of time—we thought it might stop after a few weeks, but it just kept going."
Don’t expect tech giants to release algae-powered computers in the near future, though. As shared by IGN, the microprocessor only consumes a teeny fraction of the amount a desktop computer typically uses (0.3 micro-watts per hour, in contrast with the usual range of 60 to 250 watts). It remains a proof of concept for now, but it does offer a glimmer of hope for the invention of devices made for far-flung areas.
[via ScienceAlert and IGN, images via Paolo Bombelli / University of Cambridge]