Researchers at the University of Cambridge have developed tiny 3D-printed “skyscrapers” for communities of photosynthetic bacteria that convert sunlight, carbon dioxide and water into energy.
The Cambridge researchers believe that providing these communities with the right kind of housing increases the amount of energy they can extract by more than an order of magnitude.
Photosynthetic bacteria or cyanobacteria are the most abundant life forms on Earth and need a lot of sunlight to grow, like the surface of the lake in summer. To extract the energy they produce through photosynthesis, bacteria must be attached to electrodes.
“There was a bottleneck in terms of how much energy could actually be extracted from photosynthetic systems, but nobody figured out where the bottleneck was,” said Dr. Jenny Zhang of the Department of chemistry Yusuf Hamied, who led the research. . “Most scientists assumed the bottleneck was on the biological side, in bacteria, but we found that a substantial bottleneck is actually on the hardware side“.
The researchers 3D printed custom electrodes from metal oxide nanoparticles designed to work with cyanobacteria during their photosynthesis. These electrodes were printed as strongly branched and densely populated, like a small town. The researchers say the electrodes have excellent light-handling properties, like a high-rise apartment with lots of windows.
Cyanobacteria need something to which they can attach themselves and form a community with their neighbors. The electrodes allow a balance between a lot of surface and a lot of light, like a glass skyscraper. Once the cyanobacteria self-assembled in their new home, the team found that they were more efficient than other current bioenergy technologies, such as biofuels.
The system increased the amount of energy extracted by more than an order of magnitude compared to other methods of producing bioenergy from photosynthesis. The researchers were then able to extract the bacteria’s e-waste from photosynthesis, which could be used to power small electronic devices.
“I was surprised that we were able to reach the numbers we did; Similar numbers have been predicted for many years, but this is the first time these numbers have been shown experimentally,” Zhang said. “Cyanobacteria are versatile chemical factories. Our approach allows us to exploit their conversion pathway energy at an early stage, which helps us understand how they convert energy so that we can use their natural pathways for the production of renewable or chemical fuels.
The team’s printing technique also allows for control of multiple length scales, making structures highly customizable, which could benefit a wide range of fields.