Researchers have used a widespread species of blue-green algae to power a microprocessor continuously for a year – and counting – using nothing but ambient light and water. Their system has potential as a reliable and renewable way to power small devices
The growing Internet of Things needs an increasing amount of power, and this will have to come from systems that can generate energy, rather than simply store it like batteries
The Internet of Things is a vast and growing network of electronic devices – each using only a small amount of power – that collect and share real-time data via the internet.
Using low-cost computer chips and wireless networks, many billions of devices are part of this network – from smartwatches to temperature sensors in power stations. This figure is expected to grow to one trillion devices by 2035, requiring a vast number of portable energy sources.
Powering trillions of Internet of Things devices using lithium-ion batteries maybe impractical: it would need three times more lithium than is produced across the world annually. And traditional photovoltaic devices are made using hazardous materials that have adverse environmental effects.
The system worked consistently over a long period of time – we thought it might stop after a few weeks, but it just kept going,” said Dr Paolo Bombelli in the University of Cambridge’s Department of Biochemistry, first author of the paper.The algae does not need feeding, because it creates its own food as it photosynthesises. And even though photosynthesis requires light, the device can even continue producing power during periods of darkness. This maybe because the algae processes some of its food when there’s no light, and this continues to generate an electrical current.
It’s the size of an AA battery but doesn’t have any Lithium in it.
This photosynthesis device doesn’t run down the way a battery does because it’s continually using light as the energy source.