Design, fabrication and vapor characterization of a microfabricated flexural plate resonator sensor and application to integrated sensor arrays

A chemical vapor detection and biosensor array based on microfabricated sil icon resonators coated with thin film polymer sorption layers is described. The resonators within the array are: micro-electromechanical (MEM) flexura l plate wave (FPW) sensors that have been miniaturized to allow many indepe ndently addressable sensors to be integrated within a single silicon chip. The target analyte of an individual sensor within the chip is selected by p lacing a polymer coating onto the resonating membrane. Detection is perform ed by monitoring changes in the frequency and damping factor of the resonan ce as the coating interacts with the environment. This work documents vapor response characterization of an individual sensor element within an array and reports on the operation of an eight-element sensor array. Polymer coat ings targeted toward detection of chemical weapon agents have been applied to the sensor and chemical vapor exposure tests using two chemical weapon s imulants and four vapor phase interferents have been performed. Data descri bing temperature dependence, long-term/short-term drift stability, detectio n limits, detection linearity and vapor selectivity will be presented. The use of resonant damping information is shown to provide the ability to disc riminate between vapor analytes that produce equal resonant frequency shift s. (C) 2001 Elsevier Science B.V. All rights reserved.