US Patent 7057402 - Nanotube Sensor With Integral Heater

http://www.freepatentsonline.com/7057402.pdf

There are numerous sensor applications for nanotubes which exploit the alteration of the current/voltage relationship of an array of nanotube formed between electrodes when exposed to gases or radiation. One of the drawbacks of such sensors is that forming nanotubes on a substrate requires high temperatures which may damage other electronic components involved in the sensing. This patent gets around this problem by using an integral heater preformed on the substrate to provide localized heating to form the nanotubes without damaging other preformed circuit components. Claim 1 reads:

1. A sensor comprising: a thermally isolated area on a substrate; a heating element proximate the thermally isolated area; a pair of conductors each having a portion adjacent a portion of the other; and a plurality of carbon nanotubes formed extending from one of the conductors to the other.

The heating element also facilitates gas sensing by driving off gas after sensing.