3D printing is leading the way to a new drug delivery system that only medicates patients if they have certain conditions like fever. Printed prosthetics and artificial vertebrae have already changed the world of medical science, but now the technology is being used to create tiny structures that change shape at specific temperatures. Invented by MIT researchers, the technology can be molded to a specific at one temperature without breaking to stop the spread of certain conditions in the human body. The technology isn’t quite ready for humans, but it does give a preview of a medical future where tiny devices will be able to stop illnesses from ever starting.