Claims

1-36. (canceled)

37. A method for selectively irradiating target biological cells, the method comprising: (a) providing a plurality of individually controllable electron field emitters; (b) providing an electrode operable to extract electrons from the electron field emitters; (c) determining target biological cells for irradiation; (d) identifying locations of the determined target biological cells; and (e) individually controlling electron extraction from each of the electron field emitters to selectively irradiate the identified locations for irradiating the determined target biological cells.

38. The method of claim 37 wherein the electron field emitters comprise components selected from the group consisting of a nanotube, a nanorod, a Spindt tip, and nanoparticles of diamond.

39. The method of claim 37 wherein the electron field emitters comprise carbon nanotubes.

40. The method of claim 37 wherein individually controlling electron extraction includes individually controlling a supply of voltages between each of the electron field emitters and the electrode.

41. The method of claim 37 comprising focusing the electrons emitted from the electron field emitters into a plurality of focused electron beams for irradiating the identified locations.

42. The method of claim 37 comprising: (a) providing an anode comprising a plurality of electron permeable portions corresponding to the plurality of electron field emitters; and (b) applying a voltage between the electron permeable portions and the electrode for accelerating the extracted electrons through the electron permeable portions.

43. The method of claim 37 comprising determining relative coordinates of locations that can be irradiated by the electron field emitters.

44. The method of claim 43 comprising matching at least one of the identified locations of the determined target biological cells with at least one of the relative coordinates.

45. The method of claim 44 wherein individually controlling electron extraction comprises controlling electron extraction from the electron field emitters corresponding to the at least one of the identified relative coordinates matched to the at least one of the identified locations of the determined target biological cells.

46. A method for selectively irradiating predetermined locations on biological cells, the method comprising: (a) providing a plurality of individually addressable electron field emitters; (b) providing an electrode operable to extract electrons from the electron field emitters; (c) providing an anode comprising one or more electron permeable portions corresponding to the plurality of electron field emitters; and (d) individually controlling electron extraction from each of the electron field emitters to selectively irradiate a plurality of predetermined locations on biological cells through the one or more electron permeable portions.

47. A method for manufacturing a multi-pixel electron microbeam biological cell irradiator system, the method comprising: (a) depositing a plurality of conductive contacts on a substrate, wherein the conductive contacts are spaced apart and electrically isolated from one another; (b) depositing a plurality of electron field emitters on the conductive contacts; (c) depositing a non-conductive spacer on the substrate; (d) depositing an electrode on the non-conductive spacer; and (e) providing a plurality of transistors operable to be individually controlled to apply different voltages between the conductive contacts and the electrode for individually extracting electrons from each of the electron field emitters for selectively irradiating a plurality of predetermined locations on biological cells.

48. The method of claim 47 wherein the conductive contacts comprise conductive lines.

49. The method of claim 47 wherein the substrate comprises material selected from the group consisting of silicon and glass.

50. (canceled)

51. A method for selectively irradiating target cells, the method comprising: (a) providing a plurality of individually controllable electron field emitters; (b) providing an electrode operable to extract electrons from the electron field emitters; (c) determining target cells for irradiation; (d) identifying locations of the determined target cells; (e) individually controlling electron extraction from each of the electron field emitters to selectively irradiate the identified locations for irradiating the determined target cells; (f) depositing a second non-conductive spacer on the electrode; (g) depositing a focusing electrode on the second non-conductive spacer; (h) depositing a third non-conductive spacer on the focusing electrode; and (i) depositing a collimator on the third non-conductive spacer.

52. The method of claim 51 comprising: (a) depositing a fourth non-conductive spacer on the focusing electrode; and (b) providing an anode on the third non-conductive spacer, wherein the anode includes at least one electron permeable portion.

53. (canceled)

54. A method for selectively irradiating target cells, the method comprising: (a) depositing a plurality of conductive contacts on a substrate, wherein the conductive contacts are spaced apart and electrically isolated from one another; (b) depositing a plurality of electron field emitters on the conductive contacts; (c) depositing a non-conductive spacer on the substrate; (d) depositing an electrode on the non-conductive spacer; and (e) providing a plurality of transistors operable to be individually controlled to apply different voltages between the conductive contacts and the electrode for individually extracting electrons from each of the electron field emitters for selectively irradiating predetermined locations; and (f) providing an anode on the substrate, wherein providing an anode comprises: (i) providing a substrate including an electron permeable layer on a surface thereof; and (ii) etching through the substrate to the electron permeable layer from a surface opposing the electron permeable layer.

55. A method for selectively irradiating target biological cells, the method comprising: (a) identifying a plurality of target locations of target cells on biological cells; (b) determining dosage to be used for each target location; and (c) programming a controller of a multi-pixel electron microbeam cell irradiator system to set an amplitude and duration of a gate voltage to be applied to electron field emitters on one or more cathodes such that each electron field emitter provides a predetermined amount of electrons to corresponding target locations.

56. A multi-pixel array microbeam irradiator for ex-vivo cellular irradiation of a biological sample, the microbeam irradiator comprising: (a) an array of individually addressable electron microbeam pixels; and (b) a controller operable to individually control electron microbeam emission from each of the electron microbeam emitters for selectively irradiating a biological sample at predetermined microscopic locations with respective microbeams at controlled radiation doses and dose rates.

57. The microbeam irradiator of claim 56 wherein the biological sample comprises a plurality of biological cells contained in a Petri dish, wherein specific cells of the biological cells are selected under a microscope, wherein the controller of the microbeam irradiator is configured to individually control the microbeam pixels to irradiate the selected cells with the microbeams, and wherein the controller of the microbeam irradiator is configured to control the microbeam pixels to irradiate corresponding selected cells by a respective microbeam with controlled dose and dose rate.

58. The microbeam irradiator of claim 56 wherein the biological sample comprises a plurality of biological cells, wherein the microbeam irradiator comprises an optical imaging device configured to image the biological cells before, during, and after cell irradiation for investigation of cellular and subcellular responses to high spatial and temporal resolution irradiation.

59. The microbeam irradiator of claim 56 comprising an electron-transparent window configured to vacuum-seal the microbeam irradiator and configured to allow the microbeams escape through the window to the ambient to irradiate the biological sample.

60. The microbeam irradiator of claim 59 wherein the biological sample is positioned outside the electron-transparent window in the ambient for receiving the microbeams.

61. The microbeam irradiator of claim 56 comprising a multi-pixel microbeam collimator configured to define the cross-sectional area of each microbeam.

62. The microbeam irradiator of claim 56 wherein the diameter of each microbeam escaping from the electron-transparent window is on the order of 1-100 microns.

63. The microbeam irradiator of claim 56 wherein the array of individually addressable electron microbeam pixels comprises: (i) a two-dimensional cathode array with a plurality of individually addressable electron field emitters; and (ii) an anode comprising one or more electron permeable portions corresponding to the plurality of electron field emitters; and wherein the controller is operable to individually control electron extraction from each of the electron field emitters for selectively irradiating predetermined cells or cell locations of the biological sample.

64. The microbeam irradiator of claim 63 wherein the anode is coupled to ground and the cathode is operated at a high voltage.

65. The microbeam irradiator of claim 63 comprising an electron transparent window comprising silicon nitride.

66. The microbeam irradiator of claim 63 wherein the electron field emitters comprise carbon nanotubes.

67. The microbeam irradiator of claim 63 wherein the electron field emitters comprise components selected from the group consisting of a nanotube, a carbon nanotube, a nanorod, a Spindt tip, and nanoparticles of diamond.

68. The microbeam irradiator of claim 63 comprising a gate electrode including a plurality of apertures through which electrons travel.

69. The microbeam irradiator of claim 63 comprising a focusing electrode configured to focus the electrons emitted from the electron field emitters into a plurality of focused electron beams for irradiating the predetermined microscopic locations.

70. The microbeam irradiator of claim 63 wherein a cross section of one of the electron beams is less than about 20 microns in diameter.

71. The microbeam irradiator of claim 63 wherein energy of the electrons irradiating the predetermined microscopic locations is greater than about 10 KeV.

72. The microbeam irradiator of claim 63 comprising: (a) an electrode; and (b) a power source operable to apply a voltage between the electron permeable portions and the electrode for accelerating electrons through the electron permeable portions.

73. The microbeam irradiator of claim 63 wherein the one or more electron permeable portions comprise a thin layer of nitride.

74. The microbeam irradiator of claim 63 wherein the one or more electron permeable portions comprise a thin layer of boride.

75. The microbeam irradiator of claim 63 wherein the one or more electron permeable portions comprise a thin layer of polymer.

76. A method for ex-vivo cellular irradiation of a biological sample, the microbeam irradiator comprising: (a) providing an array of individually addressable electron microbeam pixels; and (b) individually controlling electron microbeam emission from each of the electron microbeam emitters to selectively irradiate a biological sample at predetermined microscopic locations with respective microbeams at controlled radiation doses and dose rates.

77. The method of claim 76 wherein the biological sample comprises a plurality of biological cells contained in a Petri dish, and the method comprises: (a) selecting specific cells of the biological cells under a microscope; (b) individually controlling the microbeam pixels to irradiate the selected cells with the microbeams; and (c) controlling the microbeam pixels to irradiate corresponding selected cells by a respective microbeam with controlled dose and dose rate.

78. The method of claim 76 wherein the biological sample comprises a plurality of biological cells, and the method comprises imaging the biological cells with an optical imaging device before, during, and after cell irradiation for investigation of cellular and subcellular responses to high spatial and temporal resolution irradiation.

79. The method of claim 76 comprising providing an electron-transparent window configured to vacuum-seal the microbeam irradiator and configured to allow the microbeams escape through the window to the ambient to irradiate the biological sample.

80. The method of claim 79 comprising positioning the biological sample outside the electron-transparent window in the ambient for receiving the microbeams.

81. The method of claim 76 comprising providing a multi-pixel microbeam collimator configured to define the cross-sectional area of each microbeam.

82. The method of claim 76 wherein the diameter of each microbeam escaping from the electron-transparent window is on the order of 1-100 microns.

83. The method of claim 76 wherein providing an array of individually addressable electron microbeam pixels includes providing: (i) a two-dimensional cathode array with a plurality of individually addressable electron field emitters; and (ii) an anode comprising one or more electron permeable portions corresponding to the plurality of electron field emitters; and wherein the method comprises individually controlling electron extraction from each of the electron field emitters to selectively irradiate predetermined cells or cell locations of the biological sample.

84. The method of claim 83 wherein the anode is coupled to ground and the cathode is operated at a high voltage.

85. The method of claim 83 comprising providing an electron transparent window comprising silicon nitride.

86. The method of claim 83 wherein the electron field emitters comprise carbon nanotubes.

87. The method of claim 83 wherein the electron field emitters comprise components selected from the group consisting of a nanotube, a carbon nanotube, a nanorod, a Spindt tip, and nanoparticles of diamond.

88. The method of claim 83 comprising providing a gate electrode including a plurality of apertures through which electrons travel.

89. The method of claim 83 comprising providing a focusing electrode configured to focus the electrons emitted from the electron field emitters into a plurality of focused electron beams for irradiating the predetermined microscopic locations.

90. The method of claim 83 wherein a cross section of one of the electron beams is less than about 20 microns in diameter.

91. The method of claim 83 wherein energy of the electrons irradiating the predetermined microscopic locations is greater than about 10 KeV.

92. The method of claim 83 comprising: (a) providing an electrode; and (b) providing a power source operable to apply a voltage between the electron permeable portions and the electrode for accelerating electrons through the electron permeable portions.

93. The method of claim 83 wherein the one or more electron permeable portions comprise a thin layer of nitride.

94. The method of claim 83 wherein the one or more electron permeable portions comprise a thin layer of boride.

95. The method of claim 83 wherein the one or more electron permeable portions comprise a thin layer of polymer.