An ear, unsurprisingly, is difficult to make from scratch. Ear cartilage is uniquely flexible and strong and has been impossible for scientists to reproduce with synthetic prostheses. …

So why not print one?

Print-out ears may be one step closer to reality, now that scientists are figuring out how to tweak 3-D printers to craft customized ear cartilage out of living cells. Though the printable ear hasn’t been used in humans, the goal is to make these ears reliable enough to be used for children born with deformed ears, and adults who lose them from injuries. …

To make the ear, Bonassar and his colleagues scanned the ears of his twin daughters, who were 5 at the time. They used a 3-D printer to build a plastic mold based on the scan. Those printers, similar to a home inkjet, lately have also been adapted to build chocolate, guns, and even kidneys.