Apparatus and method for measuring the concentration of components in fluids
First Claim
1. An apparatus for detecting a concentration of components in a fluid, comprising:
- a semiconductor substrate having a doping polarity;
at least two diffusion regions located at a surface of said substrate;
an electrically insulating layer overlying the surface of said substrate between said diffusion regions;
a bridge member mounted to said insulating layer so as to form a gap therebetween, said bridge member allowing for passage of fluid into said gap and said bridge member being capable of having an electrical charge imposed upon it;
means for imposing an electrical charge on said bridge member; and
means for imposing an electrical potential between said diffusion regions.
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Accused Products
Abstract
An apparatus and method for measuring the concentration of various components in a fluid sample. The apparatus comprises a chemically sensitive field effect transistor (CHEMFET) having a semiconductor substrate and a pair of diffusion regions formed at the surface of the substrate. An electrical insulating layer is positioned adjacent the substrate and a fluid pervious bridge member is mounted to the insulating layer so as to form a gap between the bridge member and insulating layer. The apparatus also includes means for imposing an electrical charge on the bridge member, means for imposing an electrical potential between the diffusion regions, and means for detecting current flow between the diffusion regions. The fluid sample to be analyzed is introduced through the fluid pervious bridge member and into the gap where various components of the fluid sample are adsorbed by the bridge member, and in another embodiment, also by an adsorptive layer which is applied within the gap. The adsorptive layer can be specifically chosen so as to render the apparatus chemically selective of one or more fluid components.
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Citations
22 Claims
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1. An apparatus for detecting a concentration of components in a fluid, comprising:
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a semiconductor substrate having a doping polarity; at least two diffusion regions located at a surface of said substrate; an electrically insulating layer overlying the surface of said substrate between said diffusion regions; a bridge member mounted to said insulating layer so as to form a gap therebetween, said bridge member allowing for passage of fluid into said gap and said bridge member being capable of having an electrical charge imposed upon it; means for imposing an electrical charge on said bridge member; and means for imposing an electrical potential between said diffusion regions. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. An improved field effect transistor of the type having a semiconductor substrate with a doping polarity, at least two diffusion regions located at a surface of said substrate;
- an electrically insulating layer overlying the surface of said substrate between said diffusion regions;
an electrically conductive layer overlying the surface of said insulating layer between said diffusion regions;
means for imposing an electrical charge on said electrically conductive layer; and
means for imposing an electrical potential between said diffusion regions, wherein the improvement comprises;a bridge member mounted to the insulating layer and extending over the electrically conductive layer so as to form a gap between said bridge member and said electrically conductive layer, said bridge member allowing for passage of fluid therethrough and being capable of having an electrical charge imposed upon it; and means for imposing an electrical charge on the bridge member. - View Dependent Claims (15, 16, 17, 18, 19)
- an electrically insulating layer overlying the surface of said substrate between said diffusion regions;
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20. A method for detecting a concentration of components in a fluid, comprising the steps of:
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doping a semiconductor substrate so as to impart a doping polarity to the substrate; forming at least two diffusion regions at the surface of the substrate; insulating the surface of the substrate between the diffusion regions by placing an electrical insulating layer adjacent the substrate; mounting a bridge member to the insulating layer so as to form a gap between the bridge member and the insulating layer; imposing an electrical charge on the bridge member; imposing an electrical potential between the diffusion regions; introducing a fluid through the bridge member and into the gap between the bridge member and the insulating layer; and detecting current flow between the diffusion regions. - View Dependent Claims (21, 22)
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Specification