Sandia National Laboratories scientists have developed a versatile new material inspired by seashells that is incredibly strong, inexpensive, lightweight, and heat resistant. The material could be used in spacecraft shielding or fusion facilities.
The unusual structure of alternating layers of inorganic and organic components in seashells makes them highly durable. Organic proteins “glue” inorganic nanograin layers together, provide strength and cushioning, and prevent cracks from propagating across layers.
Sandia scientists used this structure as a model to create their unique material. In this case, the inorganic layers are silica, and the organic layers are carbon black made from burned sugar. This seemingly basic material is very tough and light, weighing only a few micrograms per layer.
According to the team, the material has a hardness of over 11 GigaPascals (GPa) and an elastic modulus (stiffness) of 120 GPa. The material also demonstrated extraordinary heat resistance, with the researchers testing it at over 2,102°F (1,150°C) and predicting that it could endure temperatures as high as 3,002°F (1,650°C).
Perhaps most crucially, the new material is extremely inexpensive to manufacture from a practical standpoint. For example, a 2-inch (5.08-cm) square of the material costs only 25 cents, compared to hundreds of dollars for a comparable-sized wafer of beryllium, which has the closest thermal and mechanical properties. And to top it off, the material is relatively eco-friendly to manufacture, requiring only the addition of ethanol during the process.
The new seashell-inspired material could be highly beneficial in spacecraft shielding, as it can resist the heat of launch and defend against collisions from small debris. Keeping weight and expenses to a minimum is particularly critical for space launches, and the novel material aids in this area.
In addition, the material could also be used to improve shielding for reactors such as Sandia’s Z Pulsed Power Facility, an experimental electromagnetic wave generator, where it can withstand an onslaught of radiation, heat, and debris.
The research was published on February 28, 2022, in MRS Advances.
