COATING FOR IMPLANTABLE BIOSENSORS

OVER THE PAST FIFTEEN YEARS NUMEROUS IMPLANTABLE BIOSENSORS HAVE BEEN DEVELOPED, BUT THEIR COMMERCIAL VIABILITY IS LIMITED MOSTLY BECAUSE OF FAILURE DUE TO TISSUE OR BODY FLUID CORROSION OVER EXTENDED PERIODS. THE CHALLENGE REMAINS TO DEVELOP A COATING MATERIAL WHICH WILL ADHERE TO THE BIOSENSOR, NOT DEGRADE IN THE PRESENCE OF AN ELECTRIC FIELD, BE THIN ENOUGH TO ALLOW FOR USE WITH MICROELECTRONICS, AND RETAIN BIOCOMPATIBILITY WITH THE HUMAN BODY. SURFACE COATINGS, SUCH AS LOW TEMPERATURE PLASMA POLYMERIZATION AND PARYLENE COATING, HAVE BEEN DEMONSTRATED TO CREATE THIN FILM SURFACES WHICH STRONGLY ADHERE TO THE SUBSTRATE (1) AND ARE POTENTIALLY VIABLE FOR CREATING A BARRIER COATING ONTO THE SURFACE OF THE IMPLANTED ELECTRODES. THE SPECIFIC AIMS OF THIS RESEARCH PLAN ARE TO DETERMINE 1. THE FEASIBILITY OF APPLYING A THIN ADHERENT POLYMER COATING OF FLUOROCARBON ONTO BIOSENSOR PROBES (OR ELECTRONICPACKAGES) BY MODIFIED PARYLENE COATING PROCESSES; AND 2. THE FEASIBILITY OF APPLYING THE ABOVE DESCRIBED METHOD TO PROVIDE A GOOD BARRIER COATING ONTO ELECTRONIC PACKAGES TO WITHSTAND CORROSION BY BODY FLUID.