Supra, a UT Austin spinout, makes 3D printed cartridges that could help build a new supply chain for rare earth elements in the U.S.—and clean up the environment. So-called rare earth elements aren’t actually rare. It’s just difficult to refine them into the purified forms that are needed for making things like electronics or clean energy tech. The standard processes are also toxic, which is one reason that the world has outsourced production to China.