Wireless Temperature Sensor Having No Electrical Connections and Sensing Method for Use Therewith

• US 20110292969A1
• Filed: 02/17/2011
• Published: 12/01/2011
• Est. Priority Date: 02/17/2010
• Status: Active Grant

• Current Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Original Assignee: Space Admi, The Government of The US As Represented By The Secretary of The Navy
• Inventors: Woodard, Marie
• Granted Patent: US 8,636,407 B2
• Time in Patent Office: Days
• US Class Current: 374/183
• CPC Class Codes: G01K 7/00 Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat giving results other than momentary value of temperature G01K3/00 ; Power supply therefor, e.g. using thermoelectric elements
• CPC Class Codes: G01K 7/38 the variations of temperature influencing the magnetic permeability

Abstract

A wireless temperature sensor includes an electrical conductor and a dielectric material on the conductor. The conductor is electrically unconnected and is shaped for storage of an electric field and a magnetic field. In the presence of a time-varying magnetic field, the conductor resonates to generate harmonic electric and magnetic field responses, each of which has a frequency associated therewith. The material is selected such that it experiences changes in either dielectric or magnetic permeability attributes in the presence of a temperature change. Shifts from the sensor'"'"'s baseline frequency response indicate that the material has experienced a temperature change.

Claims

1. A wireless temperature sensor, comprising:

an electrical conductor in the form of a thin-film trace having first and second ends and shaped to form a pattern that can store an electric field and a magnetic field, said first and second ends remaining electrically unconnected such that said electrical conductor so-shaped defines an unconnected open-circuit having inductance and capacitance wherein, in the presence of a time-varying magnetic field, said electrical conductor so-shaped resonates to generate harmonic electric and magnetic field responses, each of which has a frequency associated therewith;

a material encasing said electrical conductor, said material experiencing changes in dielectric properties in the presence of a temperature change; and

a field response recorder for wirelessly transmitting said time-varying magnetic field to said electrical conductor and for wirelessly detecting said frequency associated with said electric and magnetic field responses so-generated and resulting from said changes.

2. A wireless temperature sensor as in claim 1, wherein said dielectric material is glass.

3. A wireless temperature sensor as in claim 1, wherein said dielectric material is selected from the group consisting of borofloat and soda-lime glass.

4. A method of sensing temperature, comprising the steps of:

providing an electrical conductor in the form of a thin-film trace having first and second ends and shaped to form a pattern that can store an electric field and a magnetic field, said first and second ends remaining electrically unconnected such that said electrical conductor so-shaped defines an unconnected open-circuit having inductance and capacitance wherein, in the presence of a time-varying magnetic field, said electrical conductor so-shaped resonates to generate harmonic electric and magnetic field responses, each of which has a frequency associated therewith;

encasing said electrical conductor with a material experiencing changes in dielectric properties in the presence of a temperature change; and

wirelessly transmitting said time-varying magnetic field to said electrical conductor and wirelessly detecting said frequency associated with said electric and magnetic field responses so-generated and resulting from said changes.

5. A method of sensing temperature as in claim 4, wherein said encasing material is glass.

6. A method of sensing temperature as in claim 4, wherein said encasing material is selected from the group consisting of borofloat and soda-lime glass.