Principle and Experimental Study of a MEMS Explosive Particle Detector

Abstract

A new explosive particle detection with MEMS is presented in this paper, which utilize the properties of explosive particles. The principle of the detector is described firstly: every explosive has unique melting and evaporation point, when single explosive particle on the sensor surface melts and absorbs heat from it, the temperature change of the sensor will occurs. Unlike other indirect detecting method, a step heating method was proposed to control the working state of the sensor. The method had the advantages of easy implementation, active controlling and high selectivity: Firstly, the voltage will make the temperature of the sensor a little lower than the melting point of explosive, and the fusion of the explosive will not occur yet; With the voltage begin to increase again, the temperature of the sensor will also increase up to the melting point and produce a respond graph called base graph. The same voltage pulse was sent through the sensor before and after putting the explosive particles on the sensor surface. Absorption of heat from it during melting and evaporation causes its temperature changing and the shift on the respond graph is different from the former. Furthermore, experiments have been performed to confirm the feasibility to measure the temperature directly, and the graph is presented to show the difference between the changing with TNT sample existing or not, the resistance changing is apparent in graph when the temperature increase close to the melting point of TNT.