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A Cornell University team is progressing in 3D printing concrete underwater for a DARPA project initiated in fall 2024. The team, led by Assistant Professor Sriramya Nair, received a $1.4 million grant in May 2025 to develop seafloor sediment-based concrete.

A successful demonstration took place in September, showcasing sediment levels close to project requirements. The challenge includes overcoming cement washout underwater and managing increased viscosity from admixtures.

The final demonstration is scheduled for March, where teams will print an underwater arch to test viability for maritime deployment. Additionally, RTX Corporation's Raytheon unit has secured a DARPA contract to enhance ship defense against maritime threats, focusing on a tethered drone system integrating electro-optical sensors and command tools. This program aims to improve surveillance and decision-making for ship operators.