In a crowded room at the AAAS Annual Meeting, researchers were talking about the benefits of being able to “print” biological materials. Nearby, a machine rested on a stool, draped in a white cloth; the machine hummed as a carriage shifted back and forth, its gel-filled jet tracing a precise pattern over the flat work surface.

The talk passed into a Q&A session, and the machine hummed on. By the time questions were answered, the Fab@Home 3D printer had completed its project: a silicon model of human ear cartilage. This flash into the future of medical care was the focus of a news briefing Sunday at the Annual Meeting. The idea is based on a common inkjet printer, but this is a new approach to working with biological materials—the open-source Fab@Home includes a system that can first scan and identify the parameters of a wound. It then rebuilds the biological material one layer at a time.

Hod Lipson of Cornell University described the printing material as “ink that looks like a gel (and) you have cells embedded in that gel.”

By targeting thin biological tissue, researchers could focus on repairing even profoundly challenging wounds, such as those on burn victims. “Skin is one of the target tissues that we’re trying to translate to patients and soldiers,” said James Yoo, a professor at the Institute for Regenerative Medicine at Wake Forest University in South Carolina.

Much work and testing remains to be done before the process is ready for human use, Lipson said. An important next step would be building more complex tissues.