Gas sensor with pH-sensitive FET transducer
First Claim
1. A gas sensor comprising:
- a pH-sensitive FET transducer having a gate-insulated field-effect transistor structure;
a reference electrode deposited on the surface of said transducer and adjacent the gate region of said transducer;
an insulating tube which provides connecting lead wires to the FET transducer and to the reference electrode and which houses said transducer and reference electrode, said gate region of said FET transducer being located in the opening provided in said insulating tube, and said lead wires extending along said insulating tube;
electrical insulation resin placed between the inner wall of said tube and lead-wire-FET connecting points to stop said opening of the tube;
a hydrophilic polymer layer extending over both said gate region of the FET transducer and said reference electrode and containing electrolyte which is sensitive to variations in hydrogen ion concentration through gas absorption; and
a gas permeable membrane covering at least the entirety of said polymer layer.
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Accused Products
Abstract
A gas sensor which includes a reference electrode deposited on the surface of a pH-sensitive transducer having a gate-insulated field-effect transistor (FET) structure and adjacent a gate region of the FET, the transducer and reference electrode being housed in a flexible tube so that the gate region of the FET is located in an opening provided at the front end of or on the side wall of the tube. Lead wires connected to the FET and to the reference electrode extend along the tube. Between the inner wall of the tube and lead-wire FET bonding part is placed electrical insulation resin filling to stop the tube. A hydrophilic polymer layer containing electrolyte is provided which at least extends over both the FET gate region and a part of the reference electrode. A gas permeable membrane is laid over the polymer layer.
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Citations
18 Claims
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1. A gas sensor comprising:
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a pH-sensitive FET transducer having a gate-insulated field-effect transistor structure; a reference electrode deposited on the surface of said transducer and adjacent the gate region of said transducer; an insulating tube which provides connecting lead wires to the FET transducer and to the reference electrode and which houses said transducer and reference electrode, said gate region of said FET transducer being located in the opening provided in said insulating tube, and said lead wires extending along said insulating tube; electrical insulation resin placed between the inner wall of said tube and lead-wire-FET connecting points to stop said opening of the tube; a hydrophilic polymer layer extending over both said gate region of the FET transducer and said reference electrode and containing electrolyte which is sensitive to variations in hydrogen ion concentration through gas absorption; and a gas permeable membrane covering at least the entirety of said polymer layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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Specification