Resonant sensor capable of wireless interrogation

• US 7,922,975 B2
• Filed: 07/14/2008
• Issued: 04/12/2011
• Est. Priority Date: 07/14/2008
• Status: Active Grant

• Current Assignee: University of Dayton
• Original Assignee: University of Dayton
• Inventors: Subramanyam, Guru
• Primary Examiner(s): Griffin; Walter D
• Assistant Examiner(s): Ramdhanie; Bobby
• Application Number:
  US12/172,330
• Publication Number:
  US 20100008825A1
• Time in Patent Office: 1,002 Days
• Field of Search: 422/58, 422/82.01
• US Class Current: 422/82.01
• CPC Class Codes: G01N 27/221 by investigating the dielectric properties using microwaves G01N22/00; measuring loss factors or dielectric constants per se G01R27/26

Abstract

A resonant sensor for detecting a specific environmental analyte is presented. The resonant sensor comprises a top conductive layer of two ground conductors and a center signal line, a bottom conductive layer of two ground lines shunted together by a shunt line and a sensing layer positioned between the top conductive layer and the bottom conductive layer. A capacitor is created by the overlap of the center signal line of the top conductive layer and the shunt line of the bottom conductive layer. Electrical properties of the sensing layer change in response to binding the specific environmental analyte with the sensing layer. The sensing layer can be an electro-optic polymer. Nanoparticles or carbon nanotubes can be dispersed within the sensing layer to bind with the specific environmental analyte. An integrated antenna can be incorporated into to sensor to receive radio frequencies for wireless, passive sensing.

Claims

1. A resonant sensor for detecting a specific environmental analyte, the resonant sensor comprising a top conductive layer of two ground conductors and a center signal line, a bottom conductive layer of two ground lines shunted together by a shunt line and a sensing layer positioned between the top conductive layer and the bottom conductive layer, wherein:

the shunt line has a non-linear pattern adding inductance to the shunt line;

a capacitive area is created by the overlap of the center signal line of the top conductive layer and the shunt line of the bottom conductive layer; and

a change in electrical properties of the sensing layer in response to binding of the specific environmental analyte with the sensing layer produces a corresponding change in capacitance or leakage conductance between the top conductive layer and the bottom conductive layer or between the center signal line and the ground line, the corresponding change indicating the detection of the specific environmental analyte.

2. The resonant sensor of claim 1, wherein the shunt line and the capacitive area form an electrical circuit with a resonant frequency.

3. The resonant sensor of claim 1, wherein the sensing layer comprises an electro-optic polymer.

4. The resonant sensor of claim 3, wherein the electro-optic polymer is DNA-CTMA or BSA.

5. The resonant sensor of claim 1, wherein the sensing layer comprises a piezoelectric thin film.

6. The resonant sensor of claim 1, wherein the sensing layer comprises a three layer optical waveguide structure.

7. The resonant sensor of claim 1, wherein the specific environmental analyte is chemical, biochemical, biological or combinations thereof.

8. The resonant sensor of claim 1, wherein the specific environmental analyte is in gaseous or solid phase.

9. The resonant sensor of claim 1, wherein the specific environmental analyte is TNT or ammonia.

10. The resonant sensor of claim 1, wherein the resonant sensor is fabricated on a substrate.

11. The resonant sensor of claim 10, wherein the substrate comprises silicon, sapphire, alumina, plastic or glass.

12. The resonant sensor of claim 1, wherein the top conductive layer is perforated.

13. The resonant sensor of claim 1, wherein the top conductive layer and the bottom conductive layer comprise metal, conductive polymers, or combinations thereof.

14. The resonant sensor of claim 1, further comprising,

an integrated antenna.

15. A resonant sensor for detecting a specific environmental analyte, the resonant sensor comprising a top conductive layer of two ground conductors and a center signal line, a bottom conductive layer of two ground lines shunted together by a shunt line and an electro-optic polymer sensing layer positioned between the top conductive layer and the bottom conductive layer, wherein:

the shunt line has a non-linear pattern adding inductance to the shunt line;

the electro-optic polymer sensing layer comprises gold nanoparticles embedded in the electro-optic polymer sensing layer;

a capacitive area is created by the overlap of the center signal line of the top conductive layer and the shunt line of the bottom conductive layer; and

a change in electrical properties of the electro-optic polymer sensing layer in response to binding of the specific environmental analyte with the gold nanoparticles embedded within the electro-optic polymer sensing layer produces a corresponding change in capacitance or leakage conductance between the top conductive layer and the bottom conductive layer or between the center signal line and the ground line, the corresponding change indicating the detection of the specific environmental analyte.

16. The resonant sensor of claim 15, wherein the electro-optic polymer sensing layer comprises DNA-CTMA or BSA.

17. The resonant sensor of claim 16, wherein the specific environmental analyte is TNT or ammonia.