Fabrication and application of nanofiber ribbons and sheets and twisted and non-twisted nanofiber yarns

1. A device comprising an array of aligned conductive channels, wherein said conductive channels are operable for directional transport of species selected from the group consisting of electrons, ions, phonons, and combinations thereof and said conductive channels are provided for by nanofibers in a form selected from the group consisting of ribbons, sheets, yarns, and combinations thereof,

(i) wherein said device:

(a) is configured to provide transport of electrons;

(b) further comprises electrical contacts, said contacts provide for electrical current through the conductive channels and said electrical current is a type selected from the group consisting of alternating current, pulsed current, direct current, and combinations thereof; and

(c) is operable for use as at least one of a conductor, a transmission line, a resistor with low thermal coefficient of resistance, and a heater; and

(ii) wherein:

(a) said device is configured to provide directional transport of electrons; and

(b) the electrical current through the aligned conductive channels is anisotropic and has a ratio of the electrical current along said channels to the electrical current perpendicular to said channels larger than at least about 10, and wherein the anisotropy is provided by alignment of the aligned conductive channels.

2. A device comprising an array of aligned conductive channels, wherein said conductive channels are operable for directional transport of species selected from the group consisting of electrons, ions, phonons, and combinations thereof and said conductive channels are provided for by nanofibers in a form selected from the group consisting of ribbons, sheets, yarns, and combinations thereof,

(i) wherein said device:

(a) is configured to provide transport of electrons;

(b) further comprises electrical contacts, said contacts provide for electrical current through the conductive channels and said electrical current is a type selected from the group consisting of alternating current, pulsed current, direct current, and combinations thereof; and

(c) is operable for use as at least one of a conductor, a transmission line, a resistor with low thermal coefficient of resistance, and a heater; and

(ii) wherein:

(a) said device is operable for use as a sensor;

(b) said sensor is sensitive to changes in the electric current through said conductive channels due to an external sensing agent capable of interacting with at least one of the conductive channels;

(c) said sensor is a chemical sensor, an environmental sensor, a radiation sensor, or combinations thereof; and

(d) said device sensor is an environmental sensor operable for sensing environmental conditions selected from the group consisting of temperature, pressure, and combinations thereof.

3. The device of claim 2 , wherein said sensor is a matrix sensor, said matrix sensor is position sensitive and said matrix is provided by a combination of at least two overlapping and orthogonally-positioned sheets of the conductive channels.

4. The device of claim 1 , wherein said device provides for electromagnetic (EM) shielding of a type selected from the group consisting of reflective, absorptive, transmissive, and combinations thereof.

5. The device of claim 4 , wherein said device is integrated with a display device having a screen, the display device comprises an optically transparent nanofiber sheet coating the screen of the display to block EM radiation being emitted by the display device through the screen and the display device comprises a display element selected from a group consisting of LCD, LED, OLED, FED, cathode ray tube (CRT), and combinations thereof.

6. The device of claim 1 , wherein said device provides an antenna function for electromagnetic (EM) radiation.

7. The device of claim 1 , wherein said device is operable for transfer of heat via a transport of phonons and electrons, said device further comprises a thermal sink in thermal contact with said conductive channels and a thermal source may be applied to the device by direct thermal contact, EM radiation, optical beam, particle beam, and combinations thereof.

8. The device of claim 7 , wherein said device is operable as a thermal imaging matrix bolometer, and wherein said thermal imaging matrix bolometer is operable for measuring a distribution of temperature over a wide range from room temperature up to 3000° C.

9. A sensor comprising an elastomerically deformable carbon nanotube sheet, wherein the elastomerically deformable carbon nanotube sheet is configured to operate as a stress and strain sensor, wherein a sensor response is provided by a change in the resistance of the nanotube sheet in response to an applied stress or strain.

10. The sensor of claim 9 further comprising a conducting polymer coated on the carbon nanotube sheet or infiltrated into the carbon nanotube sheet.

11. The sensor of claim 9 further comprising a second elastomerically deformable carbon nanotube sheet and a material having high strain dependence of resistivity separating the elastomerically deformable carbon nanotube sheet from the second elastomerically deformable carbon nanotube sheet, wherein the sensor response is determined by a change in inter-sheet resistivity or a combination of inter-sheet and intra-sheet resistivity.