As reefs are threatened by climate change, Florida Tech is exploring 3D printing to potentially help maintain this critical but threatened ocean resource.

Professor of ocean engineering and marine sciences Stephen wood and research students John Carroll, Sydney Goodman, Gabija Karosas, Alexa Langley, August Neier, and Katherine Tyson suggest using a 3D printer to fabricate coral structures that would then be placed on large concrete mounds in the ocean. The goal is to design a production method in which the creation of artificial coral reefs is accessible and affordable, and the use of 3D printing would reduce the production time of artificial corals. The team is working on building a printer that is much larger than common printers on the market, which will allow them to print full-size corals.

To achieve their goals, the team assembled a smaller 3D printer to familiarize themselves with the mechanics and construction of 3D printing. They then designed a full-scale 3D printer to print in ceramic, although there is a future option to print in concrete. Mixing engineering and coral biology, the researchers looked at different 3D printer parts and filament materials for various corals and designs, and they also looked at how printed products would react in the ocean environment. The team also used a sample printer to print small models of corals, which represent the final printing concept.

While the printed corals may not look the same as the real thing, they will be designed with one important goal in mind: to make it easier for corals to grow.

“We can print the basic structure of the coral, like an Elkhorn coral, we could print a good majority of it, so when the little polyps stick together, they could grow out of that,” Wood said.

When working on artificial reefs, a big challenge is the use of potentially toxic materials. Previous structures used to attempt coral growth used trash, such as tires and PVC plastic, in hopes of reusing resources. However, chemicals from the materials interfere with growth in the area, and the materials themselves do not provide a large or stable enough surface area for microorganisms to thrive. The structures also shifted due to their small size and ended up washing up on the shores.

Another challenge encountered in building artificial reefs is the use of smaller, insecure structures, such as cinder blocks or other building blocks. While the blocks were often tied to larger mats on the seabed to hold them together, a passing storm or monsoon would scatter them on the ocean floor or bury them in the sand, disrupting any existing coral fragments. While the boulders made it easier for the corals to grow, the storm surges eventually swept them away.

Future work on the project will include installing electronics and software on the 3D printer that enable communications between the motherboard and printer electronics, as well as obtaining and updating the nomenclature to take into account the impression of clay in sandstone. After that, the team will print simple shapes and patterns from sandstone clay which will attract living coral and deploy ceramic print in the ocean to test the effectiveness of longevity in restoring the environment and wave attenuation, depending on the distance traveled by the wave as well as the depth, wavelength and height of the waves.

Coral reefs are vital habitats for marine life and key indicators of ocean health. These ecosystems provide countless benefits to the ocean and help protect shorelines through wave attenuation. In recent years, coral populations have been affected by global warming, ocean acidification, coral bleaching and many other factors. Declining coral populations have placed restoration at the forefront of environmental engineering and marine science. Several artificial reefs have already been deployed with the aim of replenishing coral reefs, and engineers are constantly discovering new ways to improve existing designs. 3D printing offers promising opportunities to reconstruct reefs quickly and efficiently.

“Standard 3D printing has a unique way of designing,” said Wood. “Anything you can think of can potentially be modeled using a 3D printer, so it extrapolates from your imagination. “