LIQUID CELL AND PASSIVATED PROBE FOR ATOMIC FORCE MICROSCOPY AND CHEMICAL SENSING

• US 20100267164A1
• Filed: 08/27/2007
• Published: 10/21/2010
• Est. Priority Date: 03/11/2003
• Status: Active Grant

• Current Assignee: Board of Regents Nevada System of Higher Education (State of Nevada)
• Original Assignee: Board of Regents Nevada System of Higher Education (State of Nevada)
• Inventors: Sulchek, Todd A., Rogers, Benjamin S., Adams, Jesse D.
• Granted Patent: US 8,136,385 B2
• Time in Patent Office: Days
• US Class Current: 436/183
• CPC Class Codes: B82Y 35/00 Methods or apparatus for measurement or analysis of nanostructures
• CPC Class Codes: G01Q 30/14 Liquid environment
• CPC Class Codes: G01Q 60/42 Functionalisation

Abstract

The invention provides a liquid cell for an atomic force microscope. The liquid cell includes a liquid cell housing with an internal cavity to contain a fluid, a plurality of conductive feedthroughs traversing the liquid cell housing between the internal cavity and a dry side of the liquid cell, a cantilevered probe coupled to the liquid cell housing, and a piezoelectric drive element disposed on the cantilevered probe. The cantilevered probe is actuated when a drive voltage is applied to the piezoelectric drive element through at least one of the conductive feedthroughs. A method of imaging an object in a liquid medium and a method of sensing a target species with the liquid cell are also disclosed.

Claims

1-35. -35. (canceled)

36. A chemical sensor system comprising:

a cantilevered probe comprising;

a piezoelectric layer;

a treated section selected to react with a chemical species;

a resistive heater thermally couplable to the treated section; and

first and second electrodes electrically coupled to the piezoelectric layer;

a driver circuit electrically coupled to the first and second electrodes and configured to actuate the cantilevered probe;

a sensing circuit electrically coupled to the first and second electrodes and configured to sense oscillation of the cantilevered probe; and

a heater circuit electrically coupled to the resistive heater;

wherein the cantilevered probe is actuated when, through the first and second electrodes, a drive voltage is applied to the piezoelectric layer by the driver circuit, the actuated cantilevered probe generating a displacement signal transmitted to the sensing circuit.

37. The sensor system of claim 36, wherein the cantilevered probe is a first cantilevered probe, the system further comprising:

a plurality of additional cantilevered probes arranged in an array together with the first cantilevered probe, each of the plurality of additional cantilevered probes comprising;

a piezoelectric layer; and

first and second electrodes electrically coupled to the piezoelectric layer;

a first electrical lead electrically coupled to the driver circuit, the sensing circuit, and each of the first electrodes of the plurality of cantilevered probes; and

a second electrical lead electrically coupled to the driver circuit, the sensor circuit, and each of the second electrodes of the plurality of cantilevered probes.

38. The sensor system of claim 36, wherein the cantilevered probe is a first cantilevered probe, the system further comprising:

a plurality of additional cantilevered probes arranged in an array together with the first cantilevered probe, each of the plurality of additional cantilevered probes comprising;

a piezoelectric layer; and

first and second electrodes electrically coupled to the piezoelectric layer;

wherein the piezoelectric layers of each of the cantilevered probes of the array are connected in series.

39. The sensor system of claim 36, wherein the cantilevered probe is a first cantilevered probe, the system further comprising:

a plurality of additional cantilevered probes arranged in an array together with the first cantilevered probe, each of the plurality of additional cantilevered probes comprising a resistive heater; and

an electrical lead electrically coupled to the heater controller and each of the resistive heaters of the cantilevered probes.

40. The sensor system of claim 36, wherein the cantilevered probe is a first cantilevered probe, the system further comprising:

a plurality of additional cantilevered probes arranged in an array together with the first cantilevered probe, each of the plurality of additional cantilevered probes comprising a resistive heater, each of the resistive heaters of the cantilevered probes being electrically coupled to one another in series.

41. The sensor system of claim 36, wherein the resistive heater is formed as one piece with the cantilevered probe.

42. The sensor system of claim 36, further comprising a passivation layer disposed on the piezoelectric layer.

43. The sensor system of claim 36, further comprising a temperature sensor in thermal communication with the cantilevered probe.

44. The sensor system of claim 36, wherein the cantilevered probe is a first cantilevered probe, the system further comprising:

a plurality of additional cantilevered probes arranged in an array together with the first cantilevered probe, each of the cantilevered probes having a different resonant frequency.

45. The sensor system of claim 36, wherein the treated section comprises a metal layer, a polymer, a water-absorbent material, a chemical-sensitive layer, a biosensitive material, a binding layer, or a combination thereof.

46. The sensor system of claim 36, wherein the cantilevered probe is a first cantilevered probe, the system further comprising:

a plurality of additional cantilevered probes arranged in an array together with the first cantilevered probe, at least two of the array of cantilevered probes having a treated section, wherein the treated sections of the cantilevered probes are each different from one another.

47. The sensor system of claim 36, wherein the cantilevered probe is a first cantilevered probe, the system further comprising:

a plurality of additional cantilevered probes arranged in an array together with the first cantilevered probe, at least one of array of cantilevered probes having a treated section and at least one of the array of cantilevered probes not having a treated section.

48. The system of claim 36, further comprising:

wherein the cantilevered probe is a first cantilevered probe, the system further comprising;

a plurality of additional cantilevered probes arranged in an array together with the first cantilevered probe; and

a housing, at least one of the array of cantilevered probes being disposed outside of the housing and at least one of the array of cantilevered probes being disposed within the housing.

49. A chemical sensor system comprising:

an array comprising a plurality of cantilevered probes, each cantilevered probe comprising;

a piezoelectric layer;

a resistive heater;

a treated section, wherein the treated sections of the plurality of cantilevered probes are different from one another;

a first electrode electrically coupled to the piezoelectric layer; and

a second electrode electrically coupled to the piezoelectric layer;

a drive circuit electrically coupled to the first and second electrodes of each of the plurality of cantilevered probes;

a sensing circuit electrically coupled to the first and second electrodes of each of the plurality of cantilevered probes; and

a heater circuit electrically coupled to the resistive heater of each of the plurality of cantilevered probes;

wherein the cantilevered probes are actuated when, through the first and second electrodes, a drive voltage is applied to the piezoelectric layer by the drive circuit thus generating a displacement signal transmitted to the sensing circuit.

50. A method of determining the composition of a sample comprising:

providing a cantilevered probe comprising;

a piezoelectric layer;

a resistive heater;

a treated section;

a first electrode electrically coupled to the piezoelectric layer; and

a second electrode electrically coupled to the piezoelectric layer;

driving the cantilevered probe by applying an excitation voltage to the piezoelectric layer;

sensing vibration of the cantilevered probe by measuring a signal generated by the piezoelectric element;

exposing the treated section to a sample; and

after exposing the treated section to the sample, sensing vibration of the cantilevered probe by measuring a signal generated by the piezoelectric element.

51. The method of claim 50 wherein exposing the treated section to a sample comprises exposing the treated section to a liquid sample.

52. The method of claim 50 further comprising heating the resistive heater to facilitate a chemical or biological reaction.

53. The method of claim 50 further comprising cleaning the cantilevered probe by heating the resistive heater.

54. The method of claim 50 further comprising:

wherein the cantilevered probe is a first cantilevered probe, the method further comprising;

providing a plurality of additional cantilevered probes arranged in an array with the first cantilevered probe, wherein each of the array of cantilevered probes has a different resonant frequency;

each of the plurality of additional cantilevered probes comprising;

a piezoelectric layer;

a first electrode in electrical communication with the piezoelectric layer; and

a second electrode in electrical communication with the piezoelectric layer;

scanning the array through the resonant frequency of each of the array of cantilevered probes.

55. The method of claim 54, wherein each cantilevered probe of the array comprises a treated section, each of the treated sections being different from one another, further comprising detecting for a plurality of chemical or biological species in the sample.

56. The method of claim 50, wherein sensing vibration of the cantilevered probe by measuring a signal generated by the piezoelectric element comprises sensing a resonant frequency of the cantilevered probe.