Reconfigurable frequency selective surfaces for remote sensing of chemical and biological agents
First Claim
1. A frequency selective surface (FSS) comprising a periodically replicated unit cell,the unit cell including a chemoresistive material having an electrical conductivity that changes in a presence of an analyte,the unit cell comprising:
- a dielectric substrate;
at least one conducting patch on the dielectric substrate; and
a chemoresistive switch comprising the chemoresistive material adjacent the conducting patch,the chemoresistive switch having a switch state related to the presence or absence of the analyte,the FSS having an electromagnetic property that is modified by a change in the switch state so as to allow detection of the analyte.
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Accused Products
Abstract
An improved frequency selective surface (FSS) comprises a periodically replicated unit cell, the unit cell including a material having a first electrical conductivity in the presence of an external condition, and a second electrical conductivity in the absence of an external condition, or in the presence of a modified external condition. For example, the material may be a chemoresistive material, having an electrical conductivity that changes in the presence of a chemical or biological analyte, i.e. having a first value of electrical conductivity in the presence of the analyte, and a second value of electrical conductivity in the absence of the analyte.
56 Citations
36 Claims
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1. A frequency selective surface (FSS) comprising a periodically replicated unit cell,
the unit cell including a chemoresistive material having an electrical conductivity that changes in a presence of an analyte, the unit cell comprising: -
a dielectric substrate; at least one conducting patch on the dielectric substrate; and a chemoresistive switch comprising the chemoresistive material adjacent the conducting patch, the chemoresistive switch having a switch state related to the presence or absence of the analyte, the FSS having an electromagnetic property that is modified by a change in the switch state so as to allow detection of the analyte. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A frequency selective surface (FSS) comprising a periodically replicated unit cell,
the unit cell including a chemoresistive material having an electrical conductivity that changes in a presence of an analyte, wherein the unit cell includes at least one dielectric slot in a conducting medium, the chemoresistive material being adjacent to the dielectric slot.
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16. A process for detecting an analyte, the process comprising:
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providing an apparatus including a frequency selective surface (FSS), the FSS comprising a periodically replicated unit cell, the unit cell comprising a dielectric substrate and a chemoresistive material, the chemoresistive material having an electrical conductivity that changes on exposure to the analyte; determining an electromagnetic property of the apparatus, the electromagnetic property being correlated with the electrical conductivity of the chemoresistive material; and detecting the analyte using the electromagnetic property. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23)
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24. A frequency selective surface (FSS), the FSS comprising a periodically replicated unit cell,
the unit cell including a chemoresistive material having an electrical conductivity that changes in a presence of an analyte, the FSS comprising: -
a dielectric substrate; an arrangement of conducting metal patches on the dielectric substrate; and at least one chemoresistive element comprising the chemoresistive material interconnecting a pair of conducting metal patches. - View Dependent Claims (25, 26, 27, 28)
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29. A frequency selective surface (FSS), the FSS comprising a periodically replicated unit cell,
the unit cell including a chemoresistive material having an electrical conductivity that changes in a presence of an analyte, wherein the unit cell includes at least one dipole slot formed in a metal screen, and a region of chemoresistive material within the metal screen.
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31. An apparatus comprising a periodic structure,
the periodic structure including a pattern of metal patches and a pattern of chemoresistive material, the apparatus having a first electromagnetic property in a presence of an analyte, and a second electromagnetic property in an absence of the analyte, a difference between the first electromagnetic property and the second electromagnetic property at least in part arising from an electrical conductivity change of the chemoresistive material, the periodic structure being a frequency selective surface (FSS).
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33. The apparatus of 31, wherein the periodic structure comprises a replicated pattern of metal patches selectively interconnected by the chemoresistive material.
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35. An apparatus including a frequency selective surface (FSS), the FSS comprising a pattern of conductive patches,
the conducting patches being selectively interconnectable by a matrix of independently addressable switches, the switches being passive switches not in electrical communication with a voltage source, the switches being responsive to an analyte, the switches having a first electrical conductivity in a presence of the analyte, and a second electrical conductivity in an absence of the analyte.
Specification