Design and application of a novel 3D printing method for bio-inspired artificial reefs

Morphological complexity and diversity are key design features for forming artificial reefs that can support marine communities. Towards this end, 3D Printing (3DP) has become a unique fabrication method in the field. In the current study, we develop a novel approach to ceramic 3DP and investigate new morphologies to form marine habitats using additive manufacturing (AM) with eco-friendly materials. A large Paste Based Extrusion (PBE) 3D printer was used in addition to adapted, ceramic materials to develop a Gravity-Stimulated Printing Design method (GSPD) to fabricate bio-inspired reef designs. This approach used a direct parametric design-tool that generates and controls a specific machine tool-path of the printer, bypassing the slicer program. The developed parametric design-tool led to highly complex shapes that assembled a spatial conglomerate structure with the variety and uniqueness of each part. A reef forming prototype made from 87 printed parts was created and installed in a coral reef environment at the northern tip of the Red Sea in the Gulf of Eilat/Aqaba. After two years, we observed abundant marine organisms settling and recruiting at a depth of 12 m to form a new reef. This study demonstrates the environmental potential of AM, specifically in ceramic 3D printing. Our results indicate that the GSPD method can be used for large-scale production of highly complex eco-friendly artificial marine habitats. Using our design approach, we can facilitate morphological complexity in ceramic AR construction that support a diversity of coral reef residents.