Researchers Power Microprocessor With Algae, Light, and Water

Researchers at the University of Cambridge have achieved an impressive feat in the field of microprocessing. The team used a widespread species of algae to power a microprocessor continuously for a year, and they did so with just ambient light and water. The new system could be a reliable and renewable method for powering small devices. 

The research was published in the journal Energy & Environmental Science. 

Powering Small System With Algae

The system is comparable in size to an AA battery, and it consists of a type of non toxic algae known as Synechocystis. This algae naturally harvests energy from the sun through the process of photosynthesis, which generates a tiny electrical current that interacts with an aluminum electrode. This is what enables the algae to power a microprocessor. 

The system is constructed out of inexpensive and mostly recyclable materials, meaning it can be replicated hundreds of thousands of times and power many small devices within the Internet of Things (IoT). According to the team, this system could be used in off-grid situations or remote locations, leveraging the small amounts of power. 

Professor Christopher Howe from the University of Cambridge’s Department of Biochemistry is senior author of the paper. 

“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 Howe. “Our photosynthetic device doesn't run down the way a battery does because it's continually using light as the energy source.”

Constructing and Testing the System

The experiment carried out by the team used the device to power an Arm Cortex M0+, a microprocessor often used in IoT devices. Operating in a domestic environment and semi-outdoor conditions under natural light and associated temperature fluctuations, the researchers were able to come up with solid results after six months of continuous power production. 

Dr. Paolo Bombelli from the University of Cambridge’s Department of Biochemistry is first author of the paper. 

“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,” said Dr. Bombelli. 

The specific type of algae used for the system does not require feeding since it creates its own food in photosynthesis. Even though photosynthesis requires light, the device is able to produce power during periods of darkness. According to the team, this could be because the algae processes some of its food in no-light conditions, which helps it continue to generate an electrical current. 

Because powering trillions of IoT devices with lithium-ion batteries is highly impractical, and traditional photovoltaic devices are made using hazardous materials that harm the environment, the new development could have big implications for the field. 

The research was a collaboration between the university and Arm, which is a leading company in microprocessor design. Arm Research was responsible for developing the Arm Cortex M0+ test chip, building the board, and setting up the data-collection cloud interface in the experiments.