Patent ID: 7894870

Claim:
A sensor suitable for implanting in living tissue for monitoring the level of a biological agent in a tissue fluid, comprising: a substrate made of a first biocompatible insulating material having a high temperature resistance selected from the group consisting of ceramic and glass/ceramic combinations; at least one conductor disposed over a preselected external surface location on the substrate and made from an electrically conductive thick film material containing particles of a metal selected from the group consisting of platinum, palladium, rhodium, ruthenium, iridium and osmium; a coating made of a second biocompatible insulating material selected from the group consisting of glass, ceramic, glass/ceramic combinations, and polymers, and formed over at least a portion of the at least one conductor to hermetically seal at least a portion of the conductor leaving at least one exposed region thereof to provide a detection electrode; and the at least one conductor consisting essentially of metal particles having been sintered by heating to a temperature within a range that extends from below a melting point of the metal particles to approximately three hundred degrees C. below the melting point of the metal particles, and having a reduced porosity that inhibits migration of the bodily fluid or any constituents thereof through the conductor; whereby instances of sensor failure and/or inaccuracy during implanted operation are minimized, wherein the at least one conductor has a helium leak value below about 1E-8 (atm cc/s).