Nanosensors are inherently more sensitive than any other kind of sensor, making them a future choice where lives are at stake. In addition, their small size and potentially low cost means that they can be widely deployed.
To detect very small amounts of chemical vapors carbon nanotubes, zinc oxide nanowires or palladium nanoparticles are used in nanotechnology-based sensors. These detecting elements work on the basis of changing the electrical characteristics when gas molecule strikes them. With these sensors a few gas molecules are sufficient to change the electrical properties of the sensing elements and hence the detection or monitoring is easy even with a very low concentration of chemical vapors. The goal is to make small and inexpensive sensors.
Various application of these sensors are in airport security concerns in the checking of vapors given off by explosive devices. These sensors can also be used in industrial plants to detect the release of harmful chemical vapors, leakage of hazardous chemical vapour, detection of specific gases and tracking of air pollution sources. Nanofabricated sensors are projected to reduce plant production costs since in most instances, they will be mounted on wireless packages, which eliminate wiring and cabling costs. Health, security, and environmental concerns will be major drivers for nanosensors. Security is the second driver for sensors and actuators. In the same way that nanosensors can provide ever more information on a person’s state of health, they can also provide more data to confirm a person’s identity or indicate the provenance of an object or document.
Hydrogen sensor have been developed with a layer of closely spaced palladium nanoparticles that are formed by a beading action. This works on the principle that when hydrogen is absorbed the palladium nanoparticles swell, causing short circuit between nanoparticles to lower the resistance of the palladium layer.
Sensors are made using a layer of gold nanoparticles on a polymer film for detecting volatile organic compounds (VOCs). This works on the principle that when the polymer swells in presence of VOCs, the spacing between the gold nanoparticles changes and the resistance of the gold layer changes.
Advancements in nanosensors have resulted in the invention of new-generation equipment as well as alternative technologies for detecting anthrax and other dangerous gases. Sensors using nanoporous silicon detection elements could detect chemical gas leaks or release of a toxin.
Nanotechnology Companies and their products
Company and its products
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 to provide a quick evaluation of their respiratory status.
Applied Nanotech: Palladium nanoparticle-based hydrogen sensor.Sensor based upon enzyme coated carbon nanotubes for analyzing chemicals in liquid samples.
Owlstone Nanotech: MEMS based sensor for detecting a wide range of gasses.