US4103227A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ion-controlled diode
Assignee: University of Pennsylvania
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Filing: 1977-03-25
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Granted: 1978-07-25
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Expires: 1997-03-25
Abstract
Abstract Disclosed is an ion-controlled device for providing an electrical indication of a specific ion concentration in a fluid. An ion-sensitive membrane is placed over the junction of a gate controlled diode whose impedance is being measured. An external reference electrode is biased such that an inversion layer forms in the semiconductor material near the ion-sensitive membrane. Changes in the concentration of the unknown ion in fluid passing over the ion-sensitive membrane will affect the inversion layer in the gate controlled diode. The change in inversion layer will result in measurable changes in the diodes impedance.
Inventors
- 👤 Jay N. Zemel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:33
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/26; G01R31/2607; G01R31/2621; G01N; G01N27/00; G01N27/26; G01N27/403; G01N27/414; G01R19/00; G01R19/08; G01R27/00; G01R27/02; G01R27/22
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
41 words
An ion sensor for sensing the presence and/or concentration of an ion in a fluid, said sensor comprising: an insulated semiconductor diode having a P/N junction; and an ion-sensitive membrane, separating said junction from said fluid and juxtaposed with said junction.
Claim 2
Dependent Claim
41 words
An ion sensor for sensing the presence and/or concentration of an ion in a fluid, said sensor comprising: an insulated semiconductor diode having a P/N junction; and an ion-sensitive membrane, separating said junction from said fluid and juxtaposed with said junction.
Claim 3
Dependent Claim
90 words
A chemical sensor, in combination with a means for measuring impedance of a semiconductor junction and a means for redistributing charges between a semiconductor diode and a membrane, for measuring the presence and concentration of a desired ion in a fluid, said sensor comprising: semiconductor diode means, having an inversion layer, for varying impedance in response to changes in said inversion layer; and membrane means, separating said diode means from said fluid, for changing the inversion layer in said diode means in response to changes in said desired ion concentration.
Claim 4
Dependent Claim
90 words
A chemical sensor, in combination with a means for measuring impedance of a semiconductor junction and a means for redistributing charges between a semiconductor diode and a membrane, for measuring the presence and concentration of a desired ion in a fluid, said sensor comprising: semiconductor diode means, having an inversion layer, for varying impedance in response to changes in said inversion layer; and membrane means, separating said diode means from said fluid, for changing the inversion layer in said diode means in response to changes in said desired ion concentration.
Claim 5
Dependent Claim
69 words
The sensor of claim 2 wherein said diode means includes N-type and P-type semiconductor material and comprises: a generally planar portion of one type semiconductor material having an upper and lower surface; a cylindrical insert of said other type semiconductor material in said planar portion forming a cylindrical P/N junction; and an insulative coating means, in combination with said membrane means, for sealing said semiconductor material from said fluid.
Claim 6
Dependent Claim
43 words
The sensor of claim 3 wherein said membrane means is located on said upper surface between said P/N junction and said fluid, and electrical contacts, connecting said N-type and P-type semiconductor materials with said means for measuring, are located on said lower surface.
Claim 7
Dependent Claim
34 words
The chemical sensor of claim 2 wherein said semiconductor diode means includes through-the-back connector means isolated from said fluid and responsive to said diode means, for making electrical contact with said semiconductor diode means.
Claim 8
Dependent Claim
110 words
A chemical sensor for sensing the presence and/or concentration of a desired chemical ion in a fluid comprising: semiconductor diode means having an inversion layer; membrane means, responsive to said diode means and said fluid and adjacent to and separating said diode means from said fluid, for reducing said inversion layer in response to said ion; means, responsive to said diode means and said membrane means, for redistributing charges between said semiconductor diode means and said membrane means; and means, responsive to said diode means, for measuring the impedance change of said semiconductor diode means, said impedance change indicative of the presence and concentration of said ion in said fluid.
Claim 9
Dependent Claim
110 words
A chemical sensor for sensing the presence and/or concentration of a desired chemical ion in a fluid comprising: semiconductor diode means having an inversion layer; membrane means, responsive to said diode means and said fluid and adjacent to and separating said diode means from said fluid, for reducing said inversion layer in response to said ion; means, responsive to said diode means and said membrane means, for redistributing charges between said semiconductor diode means and said membrane means; and means, responsive to said diode means, for measuring the impedance change of said semiconductor diode means, said impedance change indicative of the presence and concentration of said ion in said fluid.
Claim 10
Dependent Claim
34 words
The chemical sensor of claim 6 wherein said means for measuring includes: output means, responsive to said diode means, for providing a digital indication of the presence and concentration of ion in said fluid.
Claim 11
Dependent Claim
36 words
The chemical sensor of claim 6 wherein said means for measuring includes: output means, responsive to said diode means, for providing an analog output indicative of the presence and concentration of said ion in said fluid.
Claim 12
Dependent Claim
50 words
The chemical sensor of claim 6 wherein said means for redistributing charges includes: a reference electrode in said fluid at some distance from said membrane means; and potential means, electrically connected between said reference electrode and said semiconductor diode means, for producing an inversion layer in said semiconductor diode means.
Claim 13
Dependent Claim
85 words
The chemical sensor of claim 7 wherein said output means comprises: bias means, responsive to said diode means, for maintaining said semiconductor diode means in a preferred bias mode; oscillator circuit means, responsive to said semiconductor diode means, for providing an output signal the frequency of which is a function of said inversion layer in said semiconductor diode means; and frequency counter means, responsive to the output of said oscillator circuit means, for providing a digital output indicative of the ion concentration in said fluid.
Claim 14
Dependent Claim
92 words
The chemical sensor of claim 8 wherein said semiconductor diode means has capacitance and said output means comprises: capacitance measurement means, responsive to said diode means, for providing a signal indicative of changes in said semiconductor diode means capacitance; and bias supply means for biasing said semiconductor diode means and, responsive to said signal from said capacitance measurement means, for adjusting the bias of said semiconductor diode means to maintain a constant capacitance therein, said bias supply coincidentally providing an analog output indicative of the presence and/or ion concentration in said fluid.
Claim 15
Dependent Claim
33 words
The chemical sensor of claim 6 wherein said sensor further includes through-the-back connector means, isolated from said fluid, and responsive to said diode means, for making electrical contact with said semiconductor diode means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-24 | 1982-01-23 | 1982-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-24 | 1986-01-23 | 1986-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-24 | 1990-01-23 | 1990-07-25 | $7700.00 | Window Closed / Lapsed |