Nano-electronic sensors for chemical and biological analytes, including capacitance and bio-membrane devices
Embodiments of nanoelectronic sensors are described, including sensors for detecting analytes inorganic gases, organic vapors, biomolecules, viruses and the like. A number of embodiments of capacitive sensors having alternative architectures are described. Particular examples include integrated cell membranes and membrane-like structures in nanoelectronic sensors.
1. A sensor, comprising:
a substrate;
a conductive base disposed adjacent the substrate;
a dielectric material covering at least a region of the conductive base;
one or more nanostructures disposed upon the dielectric material such that at least one or more of the nanostructures are in contact with the dielectric material throughout at least most of the one or more nanostructures' length and capacitively coupled to the conductive base; and
a top lead electrically communicating to the one or more nanostructures, wherein said top lead extends substantially across the one or more nanostructures.
2. The sensor of claim 1 , wherein the one or more nanostructures comprises a network of carbon nanotubes.
3. The sensor of claim 2 further comprising a functionalization material disposed adjacent the carbon nanotubes.
4. A sensor, comprising:
a substrate;
a spaced-apart pair including a first and second conductive lead disposed adjacent the substrate;
a dielectric material covering at least a region of at least one conductive lead; and
a plurality of interconnected nanostructures disposed adjacent the dielectric material capacitively coupled to at least one conductive lead.
5. The sensor of claim 4 , wherein the one or more nanostructures comprises an electrically-continuous network including a plurality of interconnected carbon nanotubes spanning to cover at least a region of each conductive lead which separated from each lead by the dielectric material, and wherein neither conductive lead is in contact with the network of carbon nanotubes.
6. The sensor of claim 5 , wherein the spaced-apart pair of conductive leads have a characteristic separation gap “g”, and wherein the carbon nanotubes have a characteristic length “L”, and wherein “L” is significantly greater that “g”.
7. The sensor of claim 5 , wherein substantial numbers of nanotubes span the gap so as to have at least a portion of the spanning nanotube capacitively coupled to the first lead and at least a portion of the spanning nanotube capacitively coupled to the second lead.
8. The sensor of claim 4 further comprising a functionalization material disposed adjacent the carbon nanotubes.
9. The sensor of claim 4 , wherein the dielectric material comprises a plurality of layers, each layer having a distinct composition.
10. A sensor comprising:
a substrate having an active region;
first and second conductive leads disposed adjacent the substrate and spaced apart from the active region;
a dielectric material disposed adjacent at least the active region; and
first and second nanostructure layers in electrical communication with the first and second conductive leads respectively,
the nanostructure layers each including one or more nanostructures, the nanostructure layers arranged adjacent the active region and configured so as to be capacitively coupled and separated with respect to each other by the dielectric material, wherein the lengthwise dimensions of the one or more of the nanostructures are aligned generally parallel with the substrate.
11. The sensor of claim 10 , wherein the one or more of the nanostructure layers comprises a network of carbon nanotubes.
12. The sensor of claim 10 , further comprising a functionalization material disposed adjacent the carbon nanotubes.
13. The sensor of claim 10 , wherein at least a portion of the substrate and at least a portion of the dielectric material is porous and configured to permit an analyte medium to pass through the substrate active region.
14. The sensor of claim 4 , wherein the at least one conductive lead, the dielectric material, and the one or more nanostructures are disposed generally parallel to the substrate.