A Princeton University team has successfully merged electronics and biology to create a functional ear that can “hear” radio frequencies. The tissue and antenna were merged via the use of an “off-the -shelf” 3D printer, and the results have the potential to not only restore but actually enhance human hearing in the future.
The notion of cybernetics is something that has existed in science fiction for decades, and has become the focus of significant scientific research in recent years. While developments such as bionic eyes and mind-controlled prosthetic arms have allowed for the partial restoration of senses or a higher level of control, the Princeton team's efforts are a significant step forward in the field – combining electronics and biology through the use of 3D printing.
This isn't the first time that 3D printing has been used to create artificial body parts. In February this year, researchers from Cornell University announced a successful project creating realistic external ears – known as pinna – using a 3D printing technique. In that instance, the team combined collagen harvested from rat tails with cartilage cells from cow's ears to create a hydrogel which was injected into a mold, with collagen acting as a scaffolding upon which the cartilage cells could settle and grow.
The Princeton team is developing the process by using a technique whereby the electronics and biology are built and grown together in an interwoven format. This creates a form of cybernetic implant that has the potential to actually improve human hearing in the future.
The ear itself consists of a coiled antenna within a cartilage structure, with two wires leading from the base and winding around the helical “cochlea” – the area of the ear that senses sound. The signal registered by the antenna could be connected to a patient's nerve endings in a similar way to a hearing aid, restoring and improving their ability to hear.
The 3D printing technique uses computer-aided design to create the organ from thin layers of material. The stock 3D printer then combines the matrix of hydrogel and calf cells with the silver nano particles that form the antenna.
At present, the antenna is only able to detect radio waves, and requires a great deal of further testing before it can be trialled on human patients. The team hopes to refine the technology in the future, allowing the ear to register conventional acoustic sounds.
The team at Princeton has previously worked on a similar cybernetics project in which they created a removable, wireless tooth tattoo that detects harmful bacteria. The researchers commented on the importance of the work in cybernetics, stating that “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.”
Source: Princeton University
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