The ultimate goal of this project is to create chronically implantable neural interfaces that may be used to control external devices and replace lost sensory input. We are investigating conductive polymer coatings to promote more intimate connections between cells and metal electrodes, leading to a device that would be safe for long-term use and that would produce low-noise chronic single-unit recordings.

Our long-term goal is to construct an integrated device based on these coatings and the CMU CMOS-MEMS process that will entrap living cells within the device structure and use the processes of those cells as the connection to a host nervous system. To this end, we are also studying improvements to existing methods of controlling neurons in vitro such as microcontact printing of cell adhesion molecules.

Currently, we are evaluating the biocompatibility and performance of a candidate polythiophene. Our most recent results demonstrate that primary dissociated rodent neurons can grow and survive for periods of days or longer on conductive polymer self-assembled monolayers when those monolayers are doped with the neural cell adhesion molecule L1. The exact maximum duration of survival is unknown, but could be indefinite with the correct culture medium and adhesion molecule substrate. Even the limited survival observed to date enables in vitro electrophysiology to further evaluate candidate polymers.