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Mommy, where do ears come from? Someday, an acceptable answer might be “From 3-D printers that use living cells as the raw materials.” In this case, researchers at Cornell University formed a customized replacement ear using a printed soft mold that had been injected with a collagen gel. The gel contained special cow cells that produce cartilage. After a few weeks, enough cartilage had grown to replace the collagen, leaving a flexible, natural-looking ear.
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Willie Jones is an associate editor at IEEE Spectrum. In addition to editing and planning daily coverage, he manages several of Spectrum's newsletters and contributes regularly to the monthly Big Picture section that appears in the print edition.