Bionic Ear 3D-printed at Princeton

Using a petri dish, with cow cells mixed in it, and utilizing a 3-D printer, scientists at New Jersey’s Princeton University have manufactured artificial organs capable of hearing, and broadcasting, sound. And that includes sounds in ranges ordinary human ears cannot hear.

The researchers combine the cow cells with a liquid gel, and pump the resultant mixture into the printer. They then add minute pieces of silver to be coiled by the printer into an antenna. The printer program guides it to shape the organic material into an ear. The antenna can be used to both transmit and receive radio waves, which will be translated by the ear into the same data as sound waves would be.

This bionic ear is not meant to be a replacement for a human ear. The intent of it’s construction is to investigate new techniques of fusing biological matter with electronics. Once it has been printed, the ear is rubbery and can almost be seen through. For ten weeks, the synthetic organ is grown, its cells divide and increase, until a pinkish color is attained, while the tissue surrounding the antenna hardens.

The ear’s sensitivity to radio signals was testing with electrodes affixed onto the back of the ear during the printing cycle. When the scientists transmitted, via radio, a Beethoven work to the antenna of fully grown ears, the electrodes attached to them relayed the song to a set of speakers. The printed ears are capable of receiving signals at frequencies more than a million times higher than human ears.
The majority of three-dimensional printing currently produces static material such as artwork, statues, and bracelets or necklaces. There has been limited use for electronics, and in separate experiments, duplicate of human organs have been printed using the appropriate biological cells. At Princeton, this is the first use of 3-D printing combining biological with electronic components.