Blue-green algae, ambient light and water. For the past 12 months scientists at Cambridge University have used these three ingredients to run a microprocessor – which is still running. A discovery that means small devices might soon have a reliable source of renewable charge.
The new research shows algae-power might have a big role to play in helping to run the Internet of Things – which is expected to rise to a network of one trillion devices by 2035.
“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 Professor Christopher Howe, from the University of Cambridge’s Department of Biochemistry.
He added: “Our photosynthetic device doesn’t run down the way a battery does because it’s continually using light as the energy source.”
Similar in size to an AA battery, the system can run continuously thanks to an algae called Synechocystis, which converts energy from the sun through photosynthesis. The researchers found that the current this created, when connected with an aluminium electrode, could keep powering the microprocessor.
And cheap, easy to source recyclable materials are all the system needs to work. Which means they could be replicated ‘hundreds of thousands of times’ to charge small devices within the Internet of Things.
“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,” added Dr Paolo Bombelli, also from the University of Cambridge’s Department of Biochemistry.
The study, carried out by the University of Cambridge and Arm, a firm pioneering the design of microprocessors. is published today in the journal Energy & Environmental Science.