Investigation of a Nanowire Electronic Nose by Computer Simulation
Abstract
Checking planes for explosives, monitoring food quality and testing human breath for signs of disease are some of the applications of electronic noses. The ideal electronic nose would respond to a large number of chemicals over a range of concentrations. Many devices have been proposed and built which can be optimised to detect particular sets of compounds, but generally lack the ability to be tuned to detect user specified molecules while in operation. Typical devices use metal oxides, conducting polymers, piezoelectric crystal or fibre optics. Many of the mechanisms depend on rather specific chemical properties of the odorant (such as being oxidising or reducing agents), or are difficult to modify to accommodate new chemical species. This is in striking contrast to the human nose which can respond to endless new chemical species provided only that the molecules are small enough to fit the receptors. We are developing a versatile electronic nose that can be tuned to respond to a particular type of molecule simply by the application of a bias. The design is motivated by a recent theory of odorant detection in humans that was in turn inspired by Inelastic Electron Tunnelling Spectroscopy (IETS). The theory proposes that molecular recognition occurs when the exchange of energy between a molecular vibration and a mobile electron enables the electron to move from one site to another. Electronic noses are of interest to the defense of civilian flights as they can be used to detect explosives in the hold of passenger aircraft. More generally they can be used to detect the presence of molecules that could be a threat to human health. With the design proposed here, quite general scans of molecules are possible simply by sweeping the set of biases applied to an array of detectors. In this project we will investigate the properties of one freestanding nanowire TBDW
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 14, 2009
- Accession Number
- ADA524291
Entities
People
- Andrew P. Horsfield
- Lianheng Tong
Organizations
- Imperial College London