Central to coral reefs around the world is the deeply interdependent relationship between corals and algae. This interconnection is responsible for algae’s protected habitat, corals’ bright colors, and the mutual exchange of nutrients for photosynthesis. Algae growth is modulated by a process called self-shading, decreasing exposure to light. In an artificial setup, however, this process prevents researchers from growing coral quickly. To prevent this light attenuation from slowing the cultivation of microalgae, researchers at the University of Cambridge and University of California San Diego have created 3D bionic coral structures and light management systems capable of producing microalgae up to 100 times more densely than natural corals. The 3D printed, coral-inspired, photosynthetic materials prevent light attenuation through efficient absorption and redistribution of light. The study published in Nature Communications aims to create artificial coral habitats using biomaterials for more efficient cultivation of algae to use as bioenergy.

Living corals were scanned using an ultrasound technique called optical coherence tomography to create structural models. The researchers then used a custom-built 3-D bioprinting technology that uses light to mimic these intricate living photosynthetic structures and functions within seconds. The printed skeleton worked to redistribute photons and was surrounded by coral tentacle-like structures that expand the surface area for light absorption. The custom-built “optical microhabitat”  with its coral-inspired optimal-light-scattering-strategy ensured efficient delivery of light to algae cells and resulted in more effective photosynthesis.

The researchers intend to use the bionic corals for developing algae-based bioproducts for developing countries, through their company called Mantaz. Creation of these bionic microhabitats could also prevent natural habitat loss for algae (caused by coral reef death) and provide new pathways for future research regarding the coral-algae symbiotic relationship. The study also opens doors for future experiments using the bioprinting technology to aid other natural processes currently under threat due to greenhouse gas emissions.

Managing Correspondent: Rhea Grover

Press Article: 3-D-printed corals could improve bioenergy and help coral reefs on Phys.org

Original Science Article: Bionic 3D printed corals on Nature Communications

Image Credits: Tomoe Steineck via Unsplash, Nature Communications