David C. Martin, Director of the Macromolecular Science and Engineering Center at the University of Michigan, presented research on polymers that can be processed into a "fuzzy" form to enhance the compatibility of electronic implants with brain tissue.
Electrodes implanted in the brain can pick up electrical signals sent back and forth by nerve cells. The tiny devices about a millimeter long are coated with growth factors that encourage brain tissue to grow into them. The intent is for each probe to make contact with a series of neurons, allowing it to receive signals it can interpret and use to activate an external device. The technique has been called a spinal cord bypass. It could help patients with brain disorders and paralysis operate artificial limbs or control a computer mouse by simply thinking about the task.
There is, however, still a long way to go before humans will be effortlessly controlling external devices with their mind. "Our interest is in finding materials and processing schemes that can help the electrodes function better for long periods of time," Martin said.
Initial experiments in guinea pigs showed that these electrodes do not make efficient contact with the brain. "The implanted electrodes are solid, hard and smooth," Martin said, "whereas the brain is soft, wet and alive." The differences can cause the electrodes to lose contact with the brain, blocking the signal.
Martin and his team have designed rough-surfaced, fuzzy polymers with various grooves
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Contact: Sharon Worthy
s_worthy@acs.org
202-872-4371
American Chemical Society
27-Jun-2002