Bionic Ear Combines Printed Cartilage and Better-Than-Human Hearing

By Wesley Fenlon

This ear is so cyberpunk.

In the future, "lend me your ear" may be a literal thing people say to one another, not a quirky way to ask someone to pay attention to you. Researchers from John Hopkins and Princeton Universities recently collaborated on the design of a 3D printed bionic ear, which combines organic 3D printing and electronic hearing aid.

The project started with a 3D model from Thingiverse, but the bionic ear wasn't printed with the usual plastic. In their abstract, the researchers wrote "As a proof of concept, we generated a bionic ear via 3D printing of a cell-seeded hydrogel matrix in the anatomic geometry of a human ear, along with an intertwined conducting polymer consisting of infused silver nanoparticles. This allowed for in vitro culturing of cartilage tissue around an inductive coil antenna in the ear, which subsequently enables readout of inductively-coupled signals from cochlea-shaped electrodes."

This summary leads us to one of the most immediately noticeable things about the bionic ear: it looks a little creepy, like rubbery skin-that's-not-quite-skin. But the vat-grown cartilage holds up and is apparently even sturdier than the plastic mold that gave the bionic ear its shape. The embedded radio antenna could give the victim of a horrible ear-mangling accident their hearing back, although the ear currently doesn't include circuitry to convert what it picks up into an electromagnetic signal. But that's the next step.

As Ars Technica writes, the ear could also augment human hearing, doing things our normal, generally less-creepy-looking ears can't: "The researchers printed an antenna in the ear that has significant sensitivity to microwaves. This is actually a very impressive achievement, because the entire electronic circuit was printed using polymer gels (the conductive parts were silicone doped with silver nanoparticles), which generally don't cope well with radio frequency currents.

"In principle, with a bit of extra electronics, the cochlea implant would allow a human to hear radio, TV, Wi-Fi, microwave ovens, airport radar systems, and various other electromagnetic signals (much like a satellite finder)."

The future sounds cool. Hopefully it doesn't look quite so weird once we're attaching it to our heads.