Ears Team: Cornell University How it's made: Bioengineers take a 3-D scan of a child's ear, design a seven-part mold in the SolidWorks CAD program, and print the pieces. The mold is injected with a high-density gel made from 250 million bovine cartilage cells and collagen from rat tails (the latter serves as a scaffold). After 15 minutes, the ear is removed and incubated in cell culture for several days. In three months, the cartilage will have propagated enough to replace the collagen. Benefit: At least one child in 12,500 is born with microtia, a condition characterized by hearing loss due to an underdeveloped or malformed outer ear. Unlike synthetic implants, ears grown from human cells are more likely to be successfully incorporated into the body.

Courtesy Cornell University