Numerical Analysis of the Steady State in SAW Sensor Structures with Selected Polymers for Detection of DMMP and CO

The chapter presents the results of the numerical investigation of the SAW gas detector structures with selected polymer layers in steady-state conditions. The effect of SAW velocity changes vs. the surface electrical conductivity of the detector structures is predicted on the base of acoustoelectric elemental theory. The electrical surface conductivity of the rough polymer sensing layer placed above the piezoelectric waveguide depends on the profile of the diffused gas molecule concentration inside the whole detector structure. Numerical results in the steady state conditions for the gas molecules DMMP and polymer layer of (RR)-P3HT have been shown as well as for carbon oxide molecules with thin polyaniline and polypyrrole layer. The main aim of the investigations was to study a thin film’s interaction with targeted gases in the SAW detector configuration based on diffusion equations for polymers. Numerical results for profile concentration in steady state conditions for gas molecules concentration, film thickness, roughness, and interaction temperature have been shown. The results of numerical analyzes allow for selecting better detector design conditions, including the morphology of the detector layer, its thickness, operating temperature, and layer type. The numerical results, based on the code written in Python, were shown

Experimental and Numerical Acoustoelectric Investigation of the New SAW Structure with (RR)-P3HT Polymer in DMMP Detection

This document presents the results of numerical analyses of the SAW gas sensor in the steady state. The effect of SAW velocity changes depending on how the surface electrical conductivity of the sensing layer is predicted. The conductivity of roughness sensing layer above the piezoelectric waveguide depends on the profile of the diffused gas molecule concentration inside the layer. Numerical results for the gas DMMP (CAS Number 756-79-6) for layer (RR)-P3HT in the steady state are shown. The main aim of the investigations was to study the thin film interaction with target gases in the SAW sensor configuration based on diffusion equation for polymers. Numerical results for profile concentration in steady state are shown. The results of numerical acoustoelectric analysis (NAA) allow to select the sensor design conditions, including the morphology of the sensor layer, its thickness, operating temperature and layer type. The numerical results based on the code written in Python, are described and analyzed. The theoretical results were verified and confirmed experimentally

Study of Poly(3-hexyltiophene) Polymer Sensing Properties in Nerve Agent Simulant (DMMP) Detection

In the present work we report the use of regioregular poly(3-hexyltiophene) polymer (RR-P3HT) as a resistive sensor for the detection of chemical nerve agent simulant, dimethyl methylphosphonate (DMMP). The electrical response to DMMP vapour of RR-P3HT film deposited on ceramic (Al2O3) substrate in the room temperature was investigated. Results show that studied material is sensitive to DMMP trace amounts and selective against acetone and methanol. It also exhibits fast response and recovery times, repeatability and short-term stability