It’s now possible to print a bionic ear in 3D that can hear beyond the human range and all you need is off-the-shelf printing equipment—and technical expertise. A May 2, 2013 news item on Azonano provides more detail,
Scientists at Princeton University used off-the-shelf printing tools to create a functional ear that can “hear” radio frequencies far beyond the range of normal human capability.
“In general, there are mechanical and thermal challenges with interfacing electronic materials with biological materials,” said Michael McAlpine, an assistant professor of mechanical and aerospace engineering at Princeton and the lead researcher. “Previously, researchers have suggested some strategies to tailor the electronics so that this merger is less awkward. That typically happens between a 2D 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 3D interwoven format.”
McAlpine’s team has made several advances in recent years involving the use of small-scale medical sensors and antenna. Last year, a research effort led by McAlpine and Naveen Verma, an assistant professor of electrical engineering, and Fio Omenetto of Tufts University, resulted in the development of a “tattoo” made up of a biological sensor and antenna that can be affixed to the surface of a tooth.
The tooth tattoo is mentioned in my Nov. 9, 2012 posting; I focused more on Tufts University than Princeton in that piece. As for the ear (from the news item on Azonano),
The finished ear consists of a coiled antenna inside a cartilage structure. Two wires lead from the base of the ear and wind around a helical “cochlea” – the part of the ear that senses sound – which can connect to electrodes. Although McAlpine cautions that further work and extensive testing would need to be done before the technology could be used on a patient, he said the ear in principle could be used to restore or enhance human hearing. He said electrical signals produced by the ear could be connected to a patient’s nerve endings, similar to a hearing aid. The current system receives radio waves, but he said the research team plans to incorporate other materials, such as pressure-sensitive electronic sensors, to enable the ear to register acoustic sounds.
Here’s the technique the researchers used to create their bionic ear (from the news item),
Standard tissue engineering involves seeding types of cells, such as those that form ear cartilage, onto a scaffold of a polymer material called a hydrogel. However, the researchers said that this technique has problems replicating complicated three dimensional biological structures. Ear reconstruction “remains one of the most difficult problems in the field of plastic and reconstructive surgery,” they wrote.
To solve the problem, the team turned to a manufacturing approach called 3D printing. These printers use computer-assisted design to conceive of objects as arrays of thin slices. The printer then deposits layers of a variety of materials – ranging from plastic to cells – to build up a finished product. Proponents say additive manufacturing promises to revolutionize home industries by allowing small teams or individuals to create work that could previously only be done by factories.
Creating organs using 3D printers is a recent advance; several groups have reported using the technology for this purpose in the past few months. But this is the first time that researchers have demonstrated that 3D printing is a convenient strategy to interweave tissue with electronics.
The technique allowed the researchers to combine the antenna electronics with tissue within the highly complex topology of a human ear. The researchers used an ordinary 3D printer to combine a matrix of hydrogel and calf cells with silver nanoparticles that form an antenna. The calf cells later develop into cartilage.
Here’s an image of the ear,
For interested parties,a link to and a citation for the published research,
A 3D Printed Bionic Ear by Manu S Mannoor , Ziwen Jiang , Teena James , Yong Lin Kong , Karen A Malatesta , Winston Soboyejo , Naveen Verma , David H Gracias , and Michael C. McAlpine. Nano Lett., Just Accepted Manuscript DOI: 10.1021/nl4007744 Publication Date (Web): May 1, 2013
Copyright © 2013 American Chemical Society
This article is behind a paywall.
At this point, the ear is strictly for use in the laboratory they have not run any ‘in vivo’ experiments, which would be one of the next steps and a prerequisite before human clinical trials are considered.
I have written about human enhancement before, notably in my Aug. 30, 2011 posting where I highlighted this excerpt from an article by Paul Hochman,
“I don’t think I would have said this if it had never happened,” says Bailey, referring to the accident that tore off his pinkie, ring, and middle fingers. “But I told Touch Bionics I’d cut the rest of my hand off if I could make all five of my fingers robotic.” [originally excerpted from Paul Hochman's Feb. 1, 2010 article, Bionic Legs, i-Limbs, and Other Super Human Prostheses You'll Envy for Fast Company]
The Bailey quote stimulated this question for me, what would you choose if you could get an ear that hears beyond the human range?