Engineers Use 3D Printing to Speed Up Coral Reef Recovery

As bleaching and other factors jeopardise the world’s coral reefs — and the astonishing volume of ocean life they support — scientists are racing to come up with solutions.

Reefs are built over many years — from decades to millennia, in some cases — as coral gradually deposit their carbonate skeletons. Reversing and restoring damaged reefs, therefore, is a painstaking process. To date, those efforts have involved installing support structures for coral made from concrete blocks, metal frames, or even 3D-printed structures made of synthetic materials.

But when reefs are constructed at a rate of just millimetres per year, any sort of head-start can help. Bioengineers from the King Abdullah University of Science & Technology in Saudi Arabia detailed a novel 3D printing process that could do just that.

The technology, known as 3D CoraPrint, uses a newly developed photo-initiated ink that can be printed into a calcium carbonate structure. The ink can either be directly printed into large, custom structures or poured into a printed silicone mould to be replicated more quickly.

Coral micro-fragments are attached to the carbonate structure to begin the colonisation process. Because the coral don’t need to build a limestone structure underneath the carbonate, they can grow more quickly. The technique is not only rapid and reliable, engineers said, but it also mirrors the flexibility and mimicry already existing in nature.

Scientists plan to conduct additional, long-term tests of the carbonate material. But although the new method could accelerate the recovery process somewhat, it would be just one of many steps desperately needed to protect the world’s coral reefs.