University of Cambridge researchers use algae to power Arm microprocessor for a year - and say it could solve Internet of Things challenge
Could small devices be powered in future by algae?
University of Cambridge researchers have worked with Cambridge chip giant Arm to use a widespread species of blue-green algae to power a microprocessor continuously for a year - and it is still going. All the algae required was ambient light and water.
The system, similar in size to an AA battery, could be used as a reliable and renewable way to power small devices.
It works by utilising the natural harvesting of energy from the sun through photosynthesis by the non-toxic algae called Synechocystis. The process generates a tiny electrical current, which interacts with an aluminium electrode to power a microprocessor.
The researchers say it could easily be replicated hundreds of thousands of times to power large numbers of small devices as part of the Internet of Things, since the system is made of common, cheap and largely recyclable materials.
They believe it could prove particularly useful in off-grid situations or remote locations, where small amounts of power can be very beneficial.
“The growing Internet of Things needs an increasing amount of power, and we think this will have to come from systems that can generate energy, rather than simply store it like batteries,” said Prof Christopher Howe in the University of Cambridge’s Department of Biochemistry, joint senior author of the paper published in the journal Energy & Environmental Science.
“Our photosynthetic device doesn’t run down the way a battery does because it’s continually using light as the energy source.”
The device powered an Arm Cortex M0+ - a microprocessor used widely in Internet of Things devices. They tested it in a domestic environment and in semi-outdoor conditions under natural light and temperature fluctuations,
After six months of continuous power production, the results were submitted for publication.
First author Dr Paolo Bombelli, also from the Department of Biochemistry, said: “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.”
The algae creates its own food as it photosynthesises and while the process requires light, the researchers think the device can continue producing power during periods of darkness. This is thought to be because the algae processes some of its food when there is no light, continuing to generate an electrical current.
There are already billions of devices - from smartwatches to sensors - in the Internet of Things network of electronic devices, which uses low-cost computer chips and wireless networks.
By 2035, this is predicted to grow to one trillion devices.
Using lithium-ion batteries to power them would require three times more lithium than is produced across the world annually.
Meanwhile, traditional photovoltaic devices are made using hazardous materials that have a negative impact on the environment, meaning an alternative is much-needed.
Arm Research developed the ultra-efficient Arm Cortex M0+ testchip, built the board and set up the data-collection cloud interface presented in the experiments.
The research was funded by the National Biofilms Innovation Centre.