3D-Printed Ear Offers Herculean Hearing 

There are few things as precious to humans as the preservation of our senses, with sight and hearing ranking as two of the most vital faculties we have. Maintaining these senses through eyeglasses or hearing aids is often a top priority, but what if we could enhance our senses beyond that normal range?

Now, a team of scientists from Princeton University have managed to 3D print a bionic ear that is capable of “hearing” radio frequencies far beyond the what our ears can sense.

The ear may not look like much: it looks more like pink Jell-O with a yellow coiled wire stuck in the middle than a realistic replica of the human ear. But that doesn't mean it's not the next big thing to come out of biomedical engineering.

The ear was created by printing layers of cells and nanoparticles to create cartilage. Then, a cell culture was used to combine the small yellow antenna with the cartilage to make the bionic ear functional.

Bionic organs like ears and eyes have been a dream for quite some time, but previous attempts at blending the biological with the electronic has been awkward at best.

“In general, there are mechanical and thermal challenges with interfacing electronic materials with biological materials,” said Michael McAlpine, assistant professor of mechanical and aerospace engineering at Princeton, and lead researcher on the bionic ear project.

The ear in particular has developed a reputation as the one of the most difficult problems in plastic surgery due to its unique shape. Generally, tissue engineering relies on seeding a hydrogel scaffold with stem cells, but in the case of an ear 3D printing is the only way to achieve the organ's unique structure, which also helped to solve the problem of combining biological and electronic materials.

“Previously, researchers have suggested some strategies to tailor the electronics so that this merger is less awkward.” McAlpine said. “That typically happens between a 2d sheet of electronics and a surface of the tissue. However, our work suggests a new approach—to build and grow the biology up with the electronics synergistically and in a 3D interwoven format.”

“The design and implementation of bionic organs and devices that enhance human capabilities, known as cybernetics, has been an area of increasing scientific interest,” the researchers wrote in an article in Nano Letters. “This field has the potential to generate customized replacement parts for the human body, or even create organs containing capabilities beyond what human biology ordinarily provides.”

Clearly, this breakthrough is big for cybernetics, but there is certainly an added boost to the 3D printing industry as well. While it's true that 3D printing isn't new to bioengineering, this ear represents the first time that the additive manufacturing technology proved itself in the interweaving of tissue with electronics, which could mean this technology could be receiving even more attention in research to come.