Nanobatteries -- for your eyes only!
A new U.S. research center, the National Center for Design of Biomimetic Nanoconductors, has been opened to promote new ideas in the field of nanomedicine. For example, a team of researchers at Sandia National Laboratories (SNL) is developing a nano-size battery to be implanted in the eye to power artificial retina. But this center will also design and build "nanomedical devices based on natural and synthetic ion transporters -- proteins that control ion motion across the membranes of every living cell." This post is focused on the nanobattery project and its use to power an artificial retina.
Here is a short explanation about the goals of this project.
The first task for the center will be to design a class of devices for generating electric power -- bio-batteries -- for a wide array of implantable devices, starting with an artificial retina that has already been developed at the Doheny Eye Institute at the University of Southern California. The artificial retina and accompanying nanobattery will be used to correct certain types of macular degeneration.
Below is a diagram of a nanobattery that would be implanted in or near the eye (Credit: SNL). This image also appears on the home -- and only -- page of the National Center for Design of Biomimetic Nanoconductors, sponsored by the National Institute of Health.
For more information about this artificial retina project, let's switch to this article published by ScienCentral News in 2004. The 'artificial eye' uses a small camera which transmits images into the brains of people suffering from blindness. And this article gives us a solid background about this problem.
The researchers focused on blindness caused by the degeneration of the retina due to two conditions: retinitis pigmentosa (RP) and age-related macular degeneration (AMD). RP is the name given to a group of genetic eye diseases that cause the cells around the edges of the retina to deteriorate, gradually leading to what is called "tunnel vision".
In comparison, AMD, the leading cause of untreatable vision loss and legal blindness in the U.S., causes the cells in the center of the eye to deteriorate, producing a spot in the middle of the person's vision that is blurry or wavy, or completely blind, and grows progressively larger. The retinal implant, or chip, would therefore bring back peripheral vision to those with RP, and central sight to those with AMD.
The situation has certainly changed in the past 18 months, but here was the status of this project at that time.
At the moment the implant offers only minimal vision restoration. [And the team was] working on improving the implants to accommodate 60 electrodes and also 1,000 electrodes, which could give a higher resolution of sight restoration that might offer the ability to read or recognize faces.
Let's return to the SNL news release, which adds that Sandia is specifically working on the theoretical and computational sides of the project.
"We will use our expertise in multi-scale modeling to understand and predict how transporter structure leads to function, with an initial focus on specialized transporters found in the electric eel," [says principal investigator Susan Rempe.] "This information will give us a better understanding of how power is naturally created in biological organisms -- information to be used for designing and building the nanobattery."
The team plans to translate several categories of biological function into new devices that would treat disease and lead to implantable devices. Properties of interest that appear in the biological ion transporters include electrical signaling, osmotic pumping, and molecular detection.
As no date is given for the availability of such a device in the labs, it will probably take a while before an 'artificial eye' powered by a nanobattery comes to the market.
Sources: Sandia National Laboratories news release, January 12, 2006; Lindsay Carswell, ScienCentral News, April 28, 2004; and various web sites
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