Detection of Explosives Using Heated Micro-Cantilever Sensors
Abstract
The objective of this study is to demonstrate the ability to detect the presence of energetic materials by analyzing the bending response of an electrically heated micro-cantilever thermal bi-morph array. Heating the cantilevers that are made of materials with different coefficients of thermal expansion affects the bending and is measured using an optical device in real time. The detection scheme is based on the threshold value of current that results in a deviation (from the control value) of the actuation of the micro-cantilver. This threshold current is found to provide a unique signature to identify an equilibrium concentration of iso-propyl alcohol, acetone or gasoline vapors at room temperature. The threshold current is proportional with the vapor pressure of the volatile species and the ignition temperature. This shows sensors can be used for specific detection of different energetic material. The sensor array can be used to detect and identify volatile combustibles species in real time. Further, the sensor array can be multiplexed (i.e., detect multiple explosives simultaneously) and also allows redundancy checks so that false positive or false negative results can be eliminated. The sensor permits detection without coming in contact with the contaminated surface or source of the combustible material because it detects the vapors effused by the explosive materials. Thus it can be used at a nominal distance away from the source.
Citation
Koss, James R. (2009). Detection of Explosives Using Heated Micro-Cantilever Sensors. Available electronically from https : / /hdl .handle .net /1969 .1 /88039.