![](https://www.popsci.com/wp-content/uploads/2019/03/18/TXL6FE74ASD4ZGA6PMUWANVTEE.jpg?quality=85&w=2189)
![](https://www.popsci.com/wp-content/uploads/2019/03/18/TXL6FE74ASD4ZGA6PMUWANVTEE.jpg?quality=85&w=2189)
This could happen. Printing bone, muscle, and cartilage—even an ear—is easy. Anthony Atala, who heads the Wake Forest Institute for Regenerative Medicine, has done that. Organs are harder. They need to grow slowly, generating massive networks of nerves and blood vessels. Atala’s plan is to print organ molds instead. The molds have tiny holes for nutrients and oxygen to flow through as injected cells blossom into organs.
Want to know if your fantasy invention could become a reality? Tweet @PopSci, email us at letters@popsci.com, or tell us on Facebook.
This article was originally published in the May/June 2017 issue of Popular Science, under the title “I Wish Someone Would Invent…A 3D printer that builds human organs.”