This book examines both the potential application of electronic nose technology, and the current state of development of chemical sensors for the detection of vapours from explosives, such as those used in landmines. The two fields have developed, somewhat in parallel, over the past decade and so one of the purposes of this workshop, on which the book is based, was to bring together scientists from the two fields in order to challenge the two communities and, mutually, stimulate both fields.
It begins with a review of the basic principles of an electronic nose and explores possible ways in which the detection limit of conventional electronic nose technology can be reduced to the level required for the trace levels observed for many explosive materials. Next are reviews of the use of several different types of solid-state chemical sensors: polymer-based sensors, i.e. chemiluminescent, fluorescent and optical, to detect explosive materials; metal oxide semiconducting resistive sensors; and then electrochemical sensors. Next, different pattern recognition techniques are presented to enhance the performance of chemical sensors. Then biological systems are considered as a possible blue-print for chemical sensing. The biology can be employed either to understand the way insects locate odorant sources, or to understand the signal processing neural pathways. Next is a discussion of some of the new types of electronic noses; namely, a fast GC column with a SAW detector and a micromechanical sensor. Finally, the important issues of sampling technologies and the design of the microfluidic systems are considered. In particular, the use of pre-concentrators and solid phase micro extractors to boost the vapour concentration before it is introduced to the chemical sensor or electronic nose.
Review of Conventional Electronic Noses and Their Possible Application to the Detection of Explosives.- Polymer Electronics for Explosives Detection.- Luminescent Inorganic Polymer Sensors for Vapour Phase and Aqueous Detection of TNT.- Amplifying Fluorescent Polymer Arrays for Chemical Detection of Explosives.- Fast Detection of Explosives Vapours and Particles by Chemiluminescence Technique.- Optical Microsensor Arrays for Explosives Detection.- Metal Oxide Semiconductor Sensors for Detection of Toxic and Explosive Gases.- Detection of Landmines and Other Explosives with an Ultra-Trace Chemical Detector.- Electrochemical Sensing of Nitroaromatic Explosives.- Improved Sensitivity for Explosive Vapours and ICAO Taggents Detection Using Electrochemical (EC) Sensors.- Electrochemical Trace Detection and Pattern Recognition.- Detection of Dynamic Smell Intensity.- Chemotactic Search in Complex Environments.- A Spiking Neural Network Model of the Locust Antennal Lobe.- Detecting Chemical Vapours from Explosives Using the zNose®, an Ultra-High Speed Gas Chromatograph.- Explosive Vapour Detection Using Micromechanical Sensors.- Solid Phase Microextraction for Field Sampling.- A Digital Microfluidics Platform for Multiplexed Explosive Detection.- Next Generation Trace Explosives Detection Systems.- Summary of the Workshop.
