X-Hab Reef: Sustainable Carbon-Neutral Materials for 3D-Printable Coastal Infrastructure

We propose to engage in a parallel, two-track approach for Phase II in order to expedite the availability of Reefense artificial reefs to protect DoD’s coastal facilities. Track 1 of this approach will initially use our 3D Concrete Printing (“3DCP”) system and traditional concrete mixtures modified to sequester carbon, to 3D print the novel reef structures designed by the Applied Research Laboratory (“ARL”) and the University of Miami, enabling transition and commercial deployment of such reef structures as quickly as possible. Track 2 will infuse the use of the novel, low-carbon, eco-friendly material we are developing as part of our Phase 1 DARPA contract, as an alternative to traditional concrete, as soon as the requisite Technology Readiness Level (“TRL”) is achieved. Track 1 will use our 3DCP system to facilitate the design, development, and production of eco-friendly concrete reef structures being developed in the Reefense program, such as those mentioned above. 3DCP technology and its ability to rapidly and efficiently print structures not realizable via other means is critical to achieving hydrodynamically tailored performance. The ability to print with functionally graded materials enables optimizing the structural, carbon-sequestration, and marine nutrient characteristics of the printed components, all three critical to reef success. Additionally, we can use the 3DCP to create voids in the printed structure in which we can encapsulate and sequester high-carbon-emitting organic material (e.g., granulated hemp fibers). Also, our ability to use 3DCP to rapidly iterate on designs is crucial to exploring the design trade space and reducing risk. We believe that this technology can play a crucial role in helping to optimize the designs of novel reef components, and then demonstrate, test and ramp up to full-scale production. Track 2 will be undertaken in parallel with Track 1 and will continue to focus on the development of novel materials that meet all of DARPA’s Reefense objectives and can be used as an alternative to traditional grey infrastructure. Our research continues to advance with Magnesium Oxysulfate Cement (“MOSC”) material formulations incorporating novel bio-based products (i.e., hemp shives), with the objective of achieving the mechanical (i.e., compressive, and tensile strength), physical (i.e., length-change), and durability (i.e., leaching potential) properties required by DARPA, and then, utilizing these materials to produce non-leaching, carbon-negative, and marine-compatible MOSC reef starter structures. Once the novel material has achieved DARPA’s requirements, the reef structures developed for wave attenuation will be 3D printed with the novel material, which may also encapsulate the high-carbon emitting material in the voids of the structure, to achieve carbon-negative levels.