Design and Fabrication of High-Sensitive Chemical Sensor System with Preconcentration and Analysis Functions Employing a Micro Cantilever

Abstract

We report a high-sensitive chemical sensor system with preconcentration and analysis functions employing a polybutadiene (PBD) coated high-mode operative micro cantilever type mass sensor. The sensitivity, efficiency and preconcentration factor were also discussed using a simple model of adsorption system. The sensitivity of PBD coated fourth-mode operative cantilever (f=715kHz) without adsorption function was 0.295Hz/ppm for toluene, which was highest level among reported cantilever chemical sensors. This sensitivity was matched with the calculated one within 10% difference by a model using measured K-factor for PBD. The system efficiency and sensitivity was varied depending on the flow rate at desorption as the simple model implied. The system sensitivities with adsorption tube were 0.92 and 10.3(Hz/ppm)/L for ethanol and toluene, respectively. We confirmed the detection of diluted toluene of 550ppb with high concentration rate of 586 and total efficiency of 0.9.