Chemical Sensors and Nanotechnology

How can nanotechnology improve chemical vapor sensors

Nanotechnology can enable sensors to detect very small amounts of chemical vapors. Various types of detecting elements, such as carbon nanotubes, zinc oxide nanowires or palladium nanoparticles can be used in nanotechnology-based sensors. These detecting elements change their electrical characteristics, such as resistance or capacitance, when they absorb a gas molecule (for technical details see this article).

Because of the small size of nanotubes, nanowires, or nanoparticles, a few gas molecules are sufficient to change the electrical properties of the sensing elements. This allows the detection of a very low concentration of chemical vapors. The goal is to have small, inexpensive sensors that can sniff out chemicals just as dogs are used in airports to smell the vapors given off by explosives or drugs.

The capability of producing small, inexpensive sensors that can quickly identify a chemical vapor provides a kind of nano-bloodhound that doesn't need sleep or exercise which can be useful in a number of ways. An obvious application is to mount these sensors throughout an airport, or any facility with security concerns, to check for vapors given off by explosive devices.

These sensors can also be useful in industrial plants that use chemicals in manufacturing to detect the release of chemical vapors. When hydrogen fuel cells come into use, in cars or other applications, a sensor that detects escaped hydrogen could be very useful in warning of a leak. This technology should also make possible inexpensive networks of air quality monitoring stations to improve the tracking of air pollution sources.

Nanotechnology Applications under Development

Sensors using zinc oxide nano-wire detection elements capable of detecting a range of chemical vapors.

Sensors using carbon nanotube detection elements capable of detecting a range of chemical vapors.

Sensors using pallidium nanoparticle detection elements to detect hydrogen gas.

Nanotechnology Company Directory

Company	Product
Nanomix	Carbon nanotube based sensors for detecting low levels of industrial gas. Carbon nanotube based sensors for monitoring carbon dioxide and nitric oxide levels in a patient's breath. This is used to provide a quick evaluation of the respiratory status of medical patients.
Nano-Proprietary, Inc	Palladium nanoparticle-based hydrogen sensor.
Owlstone Nanotech	MEMS based sensor for detecting a wide range of gasses.

Related Nanotechnology News

Researchers at Argonne National Lab demonstrate hydrogen sensors composed of flexible plastic sheets on which nanotubes and pallidium nanoparticles have been deposited. 10/11/07

Nanomix receives $1 million grant from Department of Homeland Security to work with the Naval Research Laboratories. 01/17/07