Gas Sensor with SAW Structures

A. Laposa, M. Husak, J. Kroutil
Czech Technical University in Prague, Faculty of Electrical Engineering, CZ

Keywords: SAW, sensor, microsystems, simulation, chemical

Summary:

The objective of this paper is presents the modeling and simulation of SAW (Surface Acoustic Wave) gas sensors based on one-port and two-port interdigitated metal structures. These sensors can be used for identifying environmental contaminants in large applications scale. Various finite element models of a Surface Acoustic Wave sensors are developed using CoventorWare micro-electromechanical systems (MEMS) design and simulation tool. The impulse response model is used for determination of IDT parameters and first order investigation, the transient analysis is performed on the devices to study the acoustic wave propagation and characterize the device in time and frequency domain. The effects of the various interdigital transducer (IDT) design, intermediate layer thickness and chemical sensitivity structure on the propagation characteristics is also investigated. Also, we present some results obtained from the device using automated measurement system for SAW oscillator frequency measurement. Results indicate that our methodology provides powerfull tools to tune optimal design parameters.