Generating organs and tissue with 3D printers is nothing new. But this bioengineered ear is unique in that it utilizes embedded electronics that allow it to pick up radio frequencies outside the range of normal human hearing.
Integrating electronics with biological materials hasn’t been easy owing to heat and mechanical issues. Standard tissue engineering techniques, like cell seeding, may never lead to the creation of complex 3D biological structures that play along nicely with electronic devices.
Looking to overcome these limitations, a research team led by Princeton University’s Michael McAlpine decided to try a new approach: additive manufacturing.
To “grow” the cybernetic ear, the team turned to a standard off-the-shelf 3D printer. After a computer program modeled the structure of the ear into a series of thin slices, it was printed layer by layer using cells from a calf. Plastics and silver nanoparticles were used to architect the ear with the antenna already embedded within it. The calf cells eventually formed the cartilage.
The end product was an ear consisting of a coiled antenna inside a cartilage structure. Two wires extend out from the base which can be connected to cochlear-like electrodes — thus allowing the ear to sense incoming “sound” (or radio waves in this case).
It’s the first time that researchers have shown the effectiveness of using a 3D printer to interweave tissue with electronics.
It’s not ready for primetime just quite yet, and the current model doesn’t allow for natural human hearing. But in the future, the researchers would like to incorporate other materials, like pressure-sensitive electronic sensors, to help it sense acoustic sounds.
Once refined, the cybernetic ear could be used to restore — or even enhance — human hearing. Even in its current form, electrical signals produced by the ear could be connected to a person’s nerve endings, which is similar to how a cochlear implant works.
"The design and implementation of bionic organs and devices that enhance human capabilities... has been an area of increasing scientific interest," write the researchers in their study. "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."
Read the entire study at Nano Letters: “A 3D Printed Bionic Ear”