In an effort to one-up nature, engineers have created an artificial plant that captures carbon dioxide ten times more efficiently than its natural counterparts. And it generates enough electricity to power a lamp.
The fake plant is built with bacteria-based solar cells, and looks odd. But it offers a fun, novel concept to tackle two important issues: carbon dioxide removal and clean electricity generation.
Carbon dioxide is the main planet-warming greenhouse gas. It is also an important indoor air pollutant that threatens human health, write Maryam Rezaie and Seokheun Choi, electrical and computer engineers at the State University of New York at Binghamton, in their Advanced Sustainable Systems paper.
The European standard for a safe carbon dioxide threshold indoors is 800 parts per million (ppm). But studies report that carbon dioxide levels in indoor environments often exceed 2,500 ppm.
So the researchers set out to develop a small, maintenance-free indoor version of the expensive carbon capture systems that are being developed for outdoor capture. They decided to harness cyanobacteria, which are photosynthetic bacteria that convert carbon dioxide and water into oxygen. Choi and others have been using these organisms to make bacteria-based biobatteries.
Now, they put the bacteria into artificial leaf-shaped devices to make biological solar cells that absorb indoor light. They feed on carbon dioxide to produce oxygen and generate a small amount of electricity.
The engineers constructed an artificial plant made of five of these leaves. The leaves are connected to each other electrically via metal wires, and via channels through which water and nutrients can flow. The porous stem of the plant brings up water and nutrients from a plate below, just like in natural plants.
Researchers have made fake plants before that produce electricity by harvesting motion. The cyanobacteria-based plants used the energy from indoor light to drive photosynthesis. They reduced indoor carbon dioxide levels by 90%, from 5000 to 500 ppm, much higher than the 10% reduction that natural plants achieve. The fake plants also produced 140 microwatts of energy, enough to power an LED light.
Choi said in a press release that they want to achieve a power output of over one milliwatt. He also wants to integrate the plant with lithium-ion batteries or other type of energy-storage system.
Source: Maryam Rezaie and Seokheun Choi. Cyanobacterial Artificial Plants for Enhanced Indoor Carbon Capture and Utilization, Advanced Sustainable Systems, 2024.
Image: ©Anthropocene Magazine
