Bionic ear

From a Spiegel article: With the help of 3D printers, researchers want to produce replacement tissue. The bionic ear can even record sounds which humans can not register. It is not for implant yet, just to test the combination of materials." From the article in Nano letters: The ability to three-dimensionally interweave biological tissue with functional electronics could enable the creation of bionic organs possessing enhanced functionalities over their human counterparts. However, current electronics are inherently two dimensional, preventing seamless multidimensional integration with biology as the processes and materials used to structure synthetic tissue constructs and conventional electronic devices are very different. Here, we present a novel strategy for overcoming these difficulties via additive manufacturing of biological cells with structural and nanoparticle derived electronic elements. As a proof of concept, we generated a bionic ear via 3D printing of a cell-seeded hydrogel matrix in the precise anatomic geometry of a human ear, along with an intertwined conducting polymer consisting of infused silver nanoparticles. This allowed for the in vitro culturing of cartilage tissue around an inductive coil antenna in the ear, which subsequently connects to cochlear-like electrodes. The printed ear exhibits enhanced auditory sensing for radio frequency reception, and complementary left and right ears can listen to stereo audio music. Overall, our approach suggests a means to intricately merge biologic and nanoelectronic functionalities via 3D printing.