By using an electrically conductive polymer to coat neural implants, researchers at the University of Michigan, Ann Arbor are increasing the devices’ sensitivity.
A snippet from MIT Tech Review:
Martin [David Martin, professor at Dept. of Materials Science and Engineering @ University of Michigan –ed.] and his collaborators coat the electrodes with an electrically conductive polymer originally developed for electronic devices, such as organic LEDs and photovoltaics for solar cells. The polymer coating increases the surface area of the metal-biological interface, which in turn boosts performance of the electrode. “If you have lots of surface area, you can inject current more efficiently,” says Douglas McCreery, director of the Neural Engineering Program at the Huntington Medical Research Institute, in Pasadena, CA. “That means less demand on batteries, but, probably more importantly, you’re not recruiting the nasty electrochemical reactions that might be hazardous to surrounding tissue.”
The Michigan scientists electrochemically deposit the polymer onto the electrode, much like chroming a car bumper. By peppering the material with small amounts of another polymer, they can coax the conductive polymer to form a hairy texture along the metal shaft. Martin says that the approach mimics nature: the numerous tiny alveoli of the lungs, for example, increase the surface area available for the oxygen exchange between air and blood. Scientists can also tack on nanofibers loaded with controlled-release drugs to inhibit the inflammatory reaction.
Read more at MIT Technology Review…
Project page: Conducting Polymer Coatings for Biomedical Devices…
Image: Shown here is a slice of cortical tissue from a mouse in which the polymer (shown in blue) was deposited after insertion of the metal electrode. The polymer surrounds the cells, forming a diffuse, conductive network that follows the white-matter tracts of the cortex.