Better hearing - bionically
By Lesley Dobson , 5/13/2013
View a photo of the ‘bionic ear’: http://www.saga.co.uk/health/news/2013/may/the-bionic-3d-printable-ear-424.aspx
In a fascinating example of science catching up with fiction, scientists at Princeton University have made an ear in their laboratories that can ‘hear’. And it can detect radio frequencies far beyond the range that we can normally hear (similar to dogs being able to hear sounds at a much higher pitch than we can.)
The researchers’ main aim was to find an efficient and versatile way of merging electronics with tissue.
To do this, they used a 3-D printer. These printers use computer-assisted design (CAD) to plan a 3-D object in the form of thin slices. (This process is also known as additive manufacturing.) To create the finished product, the printer deposits layers of different materials - such as plastic and cells - to produce the finished 3-D shape, in this case, a human ear.
The researchers also used cell culture (where you grow cells in the laboratory), to combine a small coil antenna with cartilage, to produce the ‘bionic ear’.
“In general, there are mechanical and thermal challenges with interfacing electronic material with biological materials,” said Michael McAlpine, an assistant professor of mechanical and aerospace engineering at Princeton, and lead researcher on the project.”
“Previously, researchers have suggested some strategies to tailor the electronics so that this merger is less awkward. That typically happens between a 2-D sheet of electronics and a surface of the tissue. However, our work suggests a new approach – to build and grow the biology up with the electronics synergistically and in a 3-D interwoven format.”
David Gracia, an associate professor of chemical and biomolecular engineering at Johns Hopkins University and co-author on the publication, explains that bridging the divide between biology and electronics is a formidable challenge. We need to be able to overcome this to successfully create smart prostheses and implants.
“Biological structures are soft and squishy, composed mostly of water and organic molecules, while conventional electronic devices are hard and dry, composed mainly of metals, semiconductors and inorganic dielectrics,” he says.
This project is McAlpine’s team’s first attempt to create a working organ. The ability to create organs using 3-D printers is a recent development, which other groups have also been working on. However this is the first time that scientists have shown that this technique is suitable for interweaving tissue with electronics.
In this case, not only does the bionic ear reproduce human ability to hear, using electronics incorporated into the ear, it extends that ability. Potentially this could allow users to have better than human hearing.
Distributed 2013 by Northern Virginia Resource Center for Deaf and Hard of Hearing Persons (NVRC), 3951 Pender Drive, Suite 130, Fairfax, VA 22030; www.nvrc.org; 703-352-9055 V, 703-352-9056 TTY, 703-352-9058 Fax. Items in this newsletter are provided for information purposes only; NVRC does not endorse products or services. You do not need permission to share this information, but please be sure to credit NVRC. This news service is free of charge, but donations are greatly appreciated.