3-D printers in the Center for Engineering Innovation and Design (CEID) are turning out kneecaps and neurons.

University researchers, physicians and engineers are collaborating to print out breakthrough models for biomedical research and clinical application with the CEID’s five 3-D printers, which reproduce physical objects by printing layer after layer of material, often plastic or metal.

Beyond faculty research, more than 500 students have already been certified to use the entry-level 3-D printers, said Joseph Zinter, CEID’s assistant director.

“[The printers] are as modern as you can get,” said Vincent Wilczynski, deputy dean of the School of Engineering & Applied Science. “There’s definitely a role in creative usage. When students print out a product, they see the innovative and creative ways in which it can be used.”

For Gordon Shepherd, a professor of neurobiology at the Yale School of Medicine, the printers helped magnify miniscule mice neurons. This fall, Shepherd created what he suspects is the first model of a neuron with a 3-D printer, hundreds of times larger than the actual biological counterpart.

As far as future plans go, Shepherd has his eyes on printing small networks of neurons, which would allow him to see how clusters of neurons, as opposed to one singular nerve cell, process information.

“Seeing a model of a nerve cell in 3-D is a little bit like you and me looking at each other in 3-D,” Shepherd said. “It’s obviously so much better than if we just looked at each other’s picture. This is a whole new way of thinking about nerve cells in their 3-D structure and in their 3-D environment.”

Shepherd’s neuron was inspired in part by the work of Mark Michalski, a radiology resident at Yale-New Haven Hospital. He approached the CEID in the fall of 2012, looking to print 3-D organs to use as models for preoperative planning and to educate patients about their specific conditions. Among his most successful projects was the reproduction of a patient’s kneecap wrapped by a tumor.

Michalski said he first experimented with the printers out of interest alone. Gradually, he began to see the technology’s potential in terms of printing organs that could be used to improve doctor-patient communication.

“With a 3-D reconstruction, you can communicate some things very clearly that you couldn’t otherwise,” Michalski said.

Though his aspirations include printing actual human organs, Michalski’s near-term focus is on improving patient education.

To print complex organs, Michalski said the printer tackles the project segment by segment. Some body parts are easier to segment, like a bone that is relatively homogenous. Others, like a liver entangled with arteries, veins and bile ducts, are on the trickier side, he said. In order to use the printers, students are required to complete a CEID training course. This certification gives them access to use any of the center’s three entry-level machines. The other two machines — which printed the neuron and knee — require further training.

Jedidiah Thompson ’17, who uses the printers frequently and recently constructed a model of a rocket, said the neuron and kneecap demonstrate the power of the 3-D printing, though he added there is still room for improvement in the technology.

“We still have a long road ahead in terms of cutting costs, increasing resolution and decreasing failure rate,” Thompson wrote in an email to the News.

The CEID opened in September 2012.