The human body of the near-future will have spare parts in case anything is damaged. At Wake University in North Carolina, researchers say they have created a 3D printer that can produce organs, tissues and bones that could theoretically be implanted into living humans. 3D printers extrude layers of materials in a very precise pattern through a computer-controlled nozzle to make almost anything, but instead of using molten plastic or metal, Wake Forest’s printer uses what are called hydrogels—water-based solutions containing human cells. Hydrogel, along with the use of other biodegradable materials, can be used to make these replacement body parts safe and strong. So far the researchers have created an ear and a jaw bone that could be implanted into humans, and according to the researcher’s recent paper, the printed products showed no signs of necrosis, or cells dying in the tissue when tested. For all those waiting for a transplant, this could potentially be just what they need to get them healed faster.