Coral reefs play an important role in the aquatic ecosystem by providing a habitat for marine life, a food source for coastal areas, and erosion control for shorelines. Many reefs are increasingly impacted by factors such as warming waters, pollution, and natural disasters. Approaches to mitigation and remediation range from passive forms of habitat protection to the active introduction of structures that function as artificial reefs [1]. These artificial reefs are designed to prevent sedimentation of coral fragments and provide a surface for young corals to attach to, thereby increasing the survival rate of transplanted corals and supporting the natural recovery process. Here, the advantage of additive manufacturing (AM) processes for efficient reef restoration has already been demonstrated.

Due to the myriad of processes and materials available for AM, the application of the final product must be carefully considered. This paper is about the possibility of using the AM process of direct writing and clay as a material for restoring damaged coral reefs. This paper is about parameterization for safe manufacturing. In this context, the number of contours printed, the layer height, and the type of fill affect the ability of a part to maintain its shape. Here, the effects of some possible manufacturing parameters (e.g., nozzle diameter and height of the first layer) on the printed parts as well as certain manufacturing strategies (e.g., filling or number of contours) are investigated. In addition, shrinkage, a typically observed process limit, was quantified to allow better identification of design limits. Finally, a coral-inspired structure was fabricated using the identified optimal parameters.