A group of scientists at Cornell University recently printed a life-like human ear using three-dimensional printing.

Lawrence Bonassar, a professor of biomedical engineering at Cornell University, says he and his colleagues have been working with 3-D printing over the last decade. In more recent years, they've worked on making a sort of ink out of living tissue.

The ear Bonassar and his colleagues recently developed is made in part out of cartilage, a major step forward.

"Cartilage is actually one of the few tissues in the body that does not have a very large blood supply, so in the ear, the cartilage receives its nutrients from all of the blood supply of the tissue around it. And that's one of the reasons why this is particularly technically achievable right now," he said.

The ear cartilage will have the capability to develop and remodel itself, Bonassar says, which could allow these types of implants to last longer than more conventional ones made of rubber.

Bonassar said his team took a different, less conventional approach to printing this ear, printing with cells already embedded in the "ink," rather than embedding live cells into an ear that's already been printed.

"So as it sits there in the printer or as it comes out of a mold, the material itself is alive," he said.

Printing materials outside of cartilage to use for brain or skin tissue present challenges, Bonassar says, because once they're implanted into the body they would need to have a blood supply and receive proper nutrients.

"We've printed dozens of cell types with our printer. The materials that we use for printing, the ink if you will, is very hospitable to any of those cells. So the challenge is assembling them in the right configuration and implanting them under conditions that will allow them to be vascularized, grow blood vessels as quickly as possible," he said.

The funding for this research has primarily come from Cornell University, Bonassar says, but they're hoping to receive some federal support in the near future.

Three-dimensional printers are becoming increasingly popular in a number of fields, far beyond biomedical engineering, but they remain cost-prohibitive. A start-up company, FormLabs, however, is working to create a more affordable, professional 3-D printer for the public.

Max Lobovsky, the founder of FormLabs, says his company is working on a high-resolution 3-D desktop printer called the Form 1.

"What we think we've done is made the first sort of printer that has similar capabilities to printers that used to cost tens of thousands of dollars, but make it affordable for an individual user or professional and easy to use," he said.

The FormLabs Form 1 printer is similar in size to a small office printer and sells for $3,300.

Lobovsky says he envisions the Form 1 as a way to empower people to be creators who can turn their own ideas their new products.

"It's a great way to make an interesting looking, unique product because (with) 3-D printers it's not just about being able to print ... but you can also make very unusual shapes that you can't make any other way," he said.