US Patent 7230432 - Nanotube sensor with heat controlled gas removal

http://www.freepatentsonline.com/7230432.html

This patent from Honeywell teaches the use of a fairly clever construction for reusing nanotube gas sensors using heat controlled removal of gas after sensing. Claim 1 reads:

1. A method for sensing a gas/liquid, comprising: obtaining a structure having first and second terminals connected to the ends of a nanotube, respectively; exposing the nanotube to a gas/liquid; measuring a current-voltage characteristic of the nanotube; reviewing the current-voltage characteristic to obtain possible information about the gas/liquid; and heating the nanotube to desorb the gas/liquid from the nanotube.

US Patent 7176793 - Nanodetectors for cargo container security

http://www.freepatentsonline.com/7176793.pdf

There is interest in improving cargo container security since cargo containers can be used as a vessle for potentially harmful material (explosives, chemical weapons, etc.) This patent suggests the use of "nanodetectors" to assist in identifying such threats. Unfortunately the one page specification does not give much detail on the types of "nanodetectors" utilized. Claim 1 reads:

1. A detection strip for an enclosed container, comprising: a) many nano detectors for detecting materials, harmful to human beings, within an enclosed container and transmitting a corresponding resonance frequency, b) a serial number computer chip for identifying the detection strip and transmitting a corresponding resonance frequency, and c) a power source for operating the detection strip.

US Patent 7163659 - Vertical Nanowire Array Sensor

http://www.freepatentsonline.com/7163659.pdf

Nanostructures are of high interest to the area of sensors since the high surface-to-volume ratio of nanostructres allows for high precision detection of extremely small quantities. This patent from Hewlett-Packard teaches forming an array of electrically connected nanowires on a substrate to use as a chemical or bio. sensor. Claim 1 reads:


1. A sensor device, comprising: a substrate; an array of free-standing nanowires, said array comprising individual free-standing nanowires, each of said individual free-standing nanowires having a first end and a second end, said first end being attached to the substrate and said second end being unattached to the substrate, said individual free-standing nanowires configured for electrical communication with other individual free-standing nanowires through the first end; and a signal measurement apparatus electrically coupled to the array of free-standing nanowires for receiving electrical information from the array of free-standing nanowires.

However, there is some prior art in the field of scanning probe microscopy that use arrays electrically connected nanotubes as tips that might have been missed such as
http://www.freepatentsonline.com/6452171.pdf