Researchers at the University of Southern California have been trying to make a material that doesn’t respond to heat, and it seems they’re getting close. If they’re able to create this sci-fi-like unobtanium, it could have big applications in construction and engineering.
Most materials expand when they’re heated, which can be a huge engineering challenge. Large structures like bridges and buildings need to have expansion joints built in that allow the structure to expand safely without suffering damage. When objects are made from two different materials that expand at different rates when heated, they could crack or shatter. Not a great scenario when you’re talking structures that support thousands and thousands of commuting cars everyday.
So USC designed a manufacturing process where 3D-printed structure can be made from several different materials. These materials are first printed as a liquid and solidified using UV light. Using this technique, the team printed an object with an internal lattice structure with several beams arranged at specific angles. The different materials that make up the object expand at different rates, and together the expansion pulls the beams inward. The end result is that the object contracts, instead of expands, when heated.
But by using different materials and different lattice arrangements, the team hopes to customize expansion and contraction rates, and even create a material that doesn’t expand at all. It could help improve the safety and physical possibilities of bridges and buildings in cities everywhere.
Source: University of Southern California and Physical Review Letters