Chemical sensor responsive to change in volume of material exposed to target particle

• US 20040223884A1
• Filed: 05/05/2003
• Published: 11/11/2004
• Est. Priority Date: 05/05/2003
• Status: Abandoned Application

• Current Assignee: Life Safety Germany GmbH (Honeywell International Inc.)
• Original Assignee: Life Safety Germany GmbH (Honeywell International Inc.)
• Inventors: DiMeo, Frank Jr., Chen, Ing-Shin
• Application Number:
  US10/429,909
• Publication Number:
  US 20040223884A1
• Time in Patent Office: Days
• US Class Current: 422/88
• CPC Class Codes: G01N 2291/0256 Adsorption, desorption, surface mass change, e.g. on biosensors
• CPC Class Codes: G01N 29/036 by measuring frequency or resonance of acoustic waves

Abstract

A sensor comprises sensing material that changes volume when exposed to one or more target particles. The sensor also comprises a transducing platform comprising a piezoresistive component to sense change in volume of the sensing material. The sensing material is positioned over the piezoresistive component.

Claims

1. A sensor comprising:

sensing material that changes volume when exposed to one or more target particles; and

a transducing platform comprising a piezoresistive component to sense change in volume of the sensing material, wherein the sensing material is positioned over the piezoresistive component.

2. The sensor of claim 1, wherein the transducing platform comprises one of a microhotplate structure, a microcantilever structure, and a diaphragm structure.

3. The sensor of claim 1, wherein the transducing platform comprises a heater component to heat the sensing material.

4. The sensor of claim 1, in combination with a controller coupled to the transducing platform to sense a relative volume of the sensing material to identify whether a target particle is near the sensing material.

5. The sensor of claim 1, wherein a target particle is hydrogen.

6. A sensor comprising:

a first layer comprising a piezoresistive material to sense change in volume of one or more layers over the first layer; and

a second layer over the first layer, the second layer comprising material that changes volume when exposed to one or more target particles.

7. The sensor of claim 6, wherein the piezoresistive material of the first layer is to heat the second layer when current is induced to flow through the piezoresistive material.

8. The sensor of claim 7, comprising a heat distribution layer.

9. The sensor of claim 6, comprising a third layer to heat the second layer when current is induced to flow through the third layer.

10. The sensor of claim 9, comprising a heat distribution layer.

11. The sensor of claim 6, comprising a contact layer conductively coupled to the second layer.

12. The sensor of claim 6, comprising a platform to support the first and second layers over a hollowed portion of a substrate.

13. The sensor of claim 12, wherein the platform is deflectable.

14. The sensor of claim 6, comprising a membrane layer to support the first and second layers over a hollowed portion of a substrate.

15. The sensor of claim 6, wherein the first layer has two electrical leads and wherein the sensor has only the two electrical leads defined by the first layer.

16. The sensor of claim 6, wherein the first layer comprises one of polycrystalline silicon, barium titanate (BaTiO₃), silicon (Si), lead zirconium titanate ((Pb,Zr)TiO₃), and chromium nitride (CrN).

17. The sensor of claim 6, wherein the second layer comprises at least one of a rare earth element, a Group II element, lithium (Li), a Group VB element, palladium (Pd), titanium (Ti), zirconium (Zr), and a polymer.

18. The sensor of claim 6, wherein the first layer comprises polycrystalline silicon and the second layer comprises yttrium (Y).

19. The sensor of claim 6, wherein a target particle is hydrogen.

20. An apparatus comprising:

sensing material that changes volume when exposed to one or more target particles;

means for sensing change in volume of the sensing material; and

means for controlling temperature of the sensing material.

21. A sensing device comprising:

a sensor comprising a piezoresistive layer and sensing material over the piezoresistive layer, wherein the sensing material changes volume when exposed to one or more target particles; and

a controller to sense a resistance of the piezoresistive layer.

22. The sensing device of claim 21, wherein the controller comprises:

a source to energize the piezoresistive layer to heat the sensing material;

a detector to sense a resistance of the piezoresistive layer; and

control circuitry to control the source and to identify a presence of a target particle near the sensing material based on the sensed resistance of the piezoresistive layer.

23. The sensing device of claim 22, wherein the controller comprises another source to energize the sensing material.

24. The sensing device of claim 23, wherein the controller comprises another detector to sense a resistance of the sensing material;

and

wherein the control circuitry is to identify a presence of a target particle near the sensing material based on the sensed resistance of the piezoresistive layer and/or based on the sensed resistance of the sensing material.

25. The sensing device of claim 21, wherein the sensor comprises a heater layer and wherein the controller comprises:

a first source to energize the heater layer to heat the sensing material;

a second source to energize the piezoresistive layer;

a detector to sense a resistance of the piezoresistive layer; and

control circuitry to control the first source and to identify a presence of a target particle near the sensing material based on the sensed resistance of the piezoresistive layer.

26. The sensing device of claim 25, wherein the controller comprises a third source to energize the sensing material.

27. The sensing device of claim 26, wherein the controller comprises another detector to sense a resistance of the sensing material;

and

wherein the control circuitry is to identify a presence of a target particle near the sensing material based on the sensed resistance of the piezoresistive layer and/or based on the sensed resistance of the sensing material.

28. The sensing device of claim 21, wherein the piezoresistive layer comprises one of polycrystalline silicon, barium titanate (BaTiO₃), silicon (Si), lead zirconium titanate ((Pb,Zr)TiO₃), and chromium nitride (CrN).

29. The sensing device of claim 21, wherein the sensing material comprises at least one of a rare earth element, a Group II element, lithium (Li), a Group VB element, palladium (Pd), titanium (Ti), zirconium (Zr), and a polymer.

30. The sensing device of claim 21, wherein the piezoresistive layer comprises polycrystalline silicon and the sensing material comprises yttrium (Y).

31. The sensing device of claim 21, wherein a target particle is hydrogen.

32. A method comprising:

forming over a substrate a first layer comprising a piezoresistive material to sense change in volume of one or more layers over the first layer; and

forming over the first layer a second layer comprising a material that changes volume when exposed to a target particle.

33. The method of claim 32, wherein the forming the first layer comprises forming the first layer to comprise one of polycrystalline silicon, barium titanate (BaTiO₃), silicon (Si), lead zirconium titanate ((Pb,Zr)TiO₃), and chromium nitride (CrN).

34. The method of claim 32, wherein the forming the second layer comprises forming the second layer to comprise at least one of a rare earth element, a Group II element, lithium (Li), a Group VB element, palladium (Pd), titanium (Ti), zirconium (Zr), and a polymer.

35. The method of claim 32, wherein the forming the first layer comprises forming the first layer to comprise polycrystalline silicon;

and

wherein the forming the second layer comprises forming the second layer to comprise yttrium (Y).

36. The method of claim 32, wherein the forming the first layer comprises forming the piezoresistive material to heat the second layer when current is induced to flow through the piezoresistive material.

37. The method of claim 36, comprising forming a heat distribution layer.

38. The method of claim 32, comprising forming a third layer to heat the second layer when current is induced to flow through the third layer.

39. The method of claim 38, comprising forming a heat distribution layer.

40. The method of claim 32, comprising forming a contact layer for conductive coupling to the second layer.

41. The method of claim 32, comprising defining a platform to support the first and second layers over a hollowed portion of a substrate.

42. The method of claim 41, wherein the defining the platform comprises defining the platform to be deflectable.

43. The method of claim 32, comprising forming a membrane layer spanning a hollowed portion of a substrate to support the first and second layers over the hollowed portion.

44. The method of claim 32, wherein a target particle is hydrogen.

45. A method comprising:

sensing a resistance of a piezoresistive layer with sensing material over the piezoresistive layer, wherein the sensing material changes volume when exposed to one or more target particles; and

identifying whether a target particle is near the sensing material based on the sensed resistance of the piezoresistive layer.

46. The method of claim 45, comprising:

energizing the piezoresistive layer to heat the sensing material.

47. The method of claim 45, comprising:

energizing the sensing material.

48. The method of claim 45, comprising sensing a resistance of the sensing material;

wherein the identifying comprises identifying whether a target particle is near the sensing material based on the sensed resistance of the piezoresistive layer and/or based on the sensed resistance of the sensing material.

49. The method of claim 45, comprising:

energizing a heater layer to heat the sensing material.

50. A sensing device comprising:

an array of sensors, wherein at least one sensor comprises a piezoresistive layer and sensing material over the piezoresistive layer and wherein the sensing material changes volume when exposed to one or more target particles; and

a controller coupled to the array of sensors to sense a resistance of the piezoresistive layer of at least one sensor.