Thin membrane transducer

• US 7,086,288 B2
• Filed: 11/26/2003
• Issued: 08/08/2006
• Est. Priority Date: 11/27/2002
• Status: Expired due to Fees

• Current Assignee: Northwestern University
• Original Assignee: Northwestern University
• Inventors: Lee, Kyong-Hoon, Chung, JaeHyun, Lee, Junghoon
• Primary Examiner(s): PATEL, HARSHAD R
• Application Number:
  US10/723,307
• Publication Number:
  US 20040211251A1
• Time in Patent Office: 986 Days
• Field of Search: 732/042.6, 737/54, 737/20, 737/21, 737/22, 737/27, 737/77, 737/15, 737/18, 737/24, 600/347, 600/345, 600/364, 600/365
• US Class Current: 73/718
• CPC Class Codes: G01N 33/54373 involving physiochemical end-point determination, e.g. wave-guides, FETS, gratings
• CPC Class Codes: H04R 7/00 Diaphragms for electromechanical transducers in general F16J3/00; Cones for musical instruments G10 cones, diaphragms or the like, for emitting or receiving sound in general G10K13/00; Mounting thereof

Abstract

A transducer includes a substrate and a thin membrane having a shape that can be deflected relative to the substrate to provide an amount of membrane deflection useful for sensing or actuation purposes.

Claims

1. A sensor, comprising a substrate and a membrane connected to said substrate and having a membrane surface, said membrane surface having a coating comprising a reaction agent for interacting with a medium in a manner to deflect said membrane relative to said substrate, a first electrode on the substrate and spaced from the membrane, and a second electrode on or a part of the membrane and from which first electrode and second electrode a capacitance measurement can be made.

2. The sensor of claim 1 wherein said membrane has a convex or concave shape before said interacting.

3. The sensor of claim 1 wherein said surface has a chemical or biomolecular reaction agent thereon such that a reaction with species of an analyte occurs on said surface in a manner to deflect said membrane relative to said substrate.

4. The sensor of claim 1 wherein said membrane has a deflectable convex or concave shape before said interacting.

5. The sensor of claim 1 wherein the coating includes reaction molecules.

6. The sensor of claim 5 wherein the molecules provide chemical reaction sites.

7. The sensor of claim 5 wherein the molecules provide biomolecular reaction sites.

8. The sensor of claim 1 wherein the membrane includes an interior surface subjected to gas pressure to inflate the membrane to a convex shape and an exterior surface having the reaction agent thereon such that a reaction with species of an analyte occurs on said exterior surface in a manner to deflect said membrane relative to said substrate while said membrane has said convex shape imparted thereto by gas pressure inflation.

9. The sensor of claim 1 wherein the membrane is an elastomeric material.

10. The sensor of claim 1 wherein the membrane includes one or more metallic layers imparting a convex or concave shape to said membrane before said interacting.

11. The sensor of claim 1 wherein the membrane comprises a ceramic material.

12. The sensor of claim 11 wherein the ceramic material comprises silicon oxide or silicon nitride.

13. The sensor of claim 1 wherein the medium comprises an analyte.

14. A sensor, comprising a sensor area having a membrane on a substrate according to claim 1 and an actuation area in gas flow communication with the sensor area and having an actuation membrane spaced from the substrate by a gas containing gap and movable in a manner to gas pressurize said sensor area when said actuation membrane is moved toward said substrate.

15. The sensor of claim 1 having said surface on which the reaction agent interacts with a liquid or gas medium in a manner to deflect said membrane relative to said substrate.

16. A sensor comprising a substrate and a membrane connected to said substrate and having a surface with a coating comprising a reaction agent for interacting with a medium a manner to deflect said membrane relative to said substrate, a first electrode on the substrate and spaced from the membrane, and a second electrode on or a part of the membrane and from which first electrode and second electrode a capacitance measurement can be made, and further having a dummy membrane connected to the substrate and having a surface on which no interaction with said medium occurs, a third electrode on the substrate spaced from the dummy membrane, and a fourth electrode on or a part of the dummy membrane and from which third electrode and fourth electrode a capacitance measurement can be made.

17. A transducer, comprising a substrate and a membrane having a surface with a coating comprising a reaction agent and peripherally connected to said substrate and being deflectable relative to said substrate by an interaction of the reaction agent with a medium occurring on said membrane surface, a first electrode on the substrate and spaced from the membrane, and a second electrode on or part of the membrane and from which first electrode and second electrode a capacitance measurement can be made.

18. A method of sensing, comprising producing an interaction between a medium and a reaction agent of a coating on a surface of a membrane connected to a substrate, deflecting the membrane in response to the interaction, and detecting the deflection of the membrane by measuring a change in capacitance between a first electrode on the substrate and a second electrode on or a part of the membrane.

19. The method of claim 18 wherein said interaction comprises a chemical and/or biomolecular reaction between an agent on said surface and molecules in an analyte.

20. A method of sensing, comprising producing an interaction between a medium and a reaction agent of a coating on a surface of a membrane connected to a substrate while said membrane is inflated by gas pressure to impart a deflectable shape thereto, deflecting the membrane in response to the interaction, and detecting the deflection of the membrane by measuring a change in capacitance between a first electrode on the substrate and a second electrode on or a part of the membrane.