The world of 3D printing has been experiencing a boom, with creative people everywhere realizing the potential of the process. Now 3D printing has made its way into the medical world, with scientists at Cornell University developing life-like ears to treat three different patients: children born with an ear deformity called microtia, people who lost their external ear in an accident, or victims of cancer who suffered ear damage. Artificial tissue is made with collagen from rat tails and cartilage from cow ears. High density gel is injected into a mold and viola! You have an ear. Learn more with the video below.