Scientists at the University of Cambridge in England used algae to keep a computer running continuously for a year.
According to the institution, the system was similar in size to an AA battery and contained a non-toxic species of blue-green algae called synechocystis.
The alga “naturally harvests energy from the sun through photosynthesis,” the university said.
The researchers believe the system “has potential as a reliable and renewable way to power small devices.”
They said the system was made from “common, cheap and widely recyclable materials”.
“This means it can be easily replicated hundreds of thousands of times to power a large number of small devices as part of the Internet of Things,” they said.
The Internet of Things is a vast and growing network of electronic devices that use a small amount of energy that collect and share data in real time via the internet, such as smartwatches.
The electrical current generated by photosynthesis interacts with an aluminum electrode that is used to power the microprocessor.
Professor Christopher Howe, from the Department of Biochemistry at the University of Cambridge, said: “Our photosynthetic device does not work like a battery because it is continually using light as a source of energy.”
In the experiment, the device was used to power an Arm Cortex M0+, which is a microprocessor widely used in Internet of Things devices.
Arm, a Cambridge-based microprocessor design company, collaborated with Cambridge researchers on the project.
Paolo Bombelli, also from the University of Cambridge’s 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 continued.”
