US 5,518,601 A · Extended use planar sensors

Abstract

A planar, solid-state electrochemical oxygen sensor having a substrate, conductive strips deposited on the substrate, and a dielectric layer insulating portions of the conductive strips except those portions which define a working electrode and at least one second electrode. The working electrode may be defined by an open printed region of the dielectric, or by a needle-punched or laser-burned hole or opening in the dielectric which exposes a small region of one of the conductive strips. A solid electrolyte contacting the electrodes is covered by a semipermeable membrane which may comprise an acrylonitrile butadiene copolymer or an acrylate-based copolymer. A sample chamber is defined by the membrane, a cover member, and a gasket therebetween, and has a volume of from about 1 to about 2 N.L. The gasket is formulated from the highly cross-linked polymerization product of epichlorohydrin. All sensor components are selected such that a sensor operable for at least 2 days under normal conditions is produced.

Claims3

Dependent claims

A method for forming a microelectrode for use as a working electrode in a planar, solid-state sensor or the like, comprising the steps of:

selecting an electrically nonconductive substrate,
combining said substrate with an electrically conductive material with said electrically conductive material forming a layer adjacent said electrically nonconductive substrate,
coating at least a portion of the electrically conductive material with an electrically insulating material,
puncturing the electrically insulating material to form at least one hole or opening therein with a needle in communication with electric circuit means in communication with the electrically conductive material, which moves between a first position and a second position in which the electric circuit means generates a signal;
withdrawing the needle when the signal is generated;
said insulating material being selected to firmly adhere to the conductive material such that when the at least one hole or opening is formed, an exposed, electrically addressable portion of the electrically conductive material is created, defining at least one electrode having a size defined by the cross-sectional area of the hole or opening.

3 more elements

Dependencies are inferred from the claim text.

Extended use planar sensors

Life of this patent

Extended use planar sensors

Life of this patent

Abstract

Claims3