RMIT engineers develop floating 3D-printed titanium material

Engineers at RMIT University have developed a 3D-printed titanium lattice material that remains buoyant in water, even when sustaining significant damage or cracks. The research, published in the journal ‘Advanced Materials’, introduces the first reported demonstration of a floating metal-hybrid lattice metamaterial.

The structure consists of hollow, interconnected titanium struts that are filled with polyurethane foam. This design allows water to flow through the external openings of the lattice while the foam-filled internal channels maintain buoyancy. To predict whether such open structures will float, the team developed a new measurement called ‘skeletal density’, which calculates the density of only the parts of the structure that exclude water.

Testing showed the material is 70% stronger than stainless steel or high-density polyethylene at the same overall density. In seawater corrosion tests, the structure showed minimal mass loss and strength decline. This breakthrough could significantly impact the manufacturing of marine infrastructure, including buoys, jetties, and floating sensors.