Equivalent circuit of polypyrrole-based QCM

Equivalent circuit of polypyrrole-based QCM

Paper in proceedings (conference paper)

Quartz crystal microbalance belongs to a group of high-sensitive chemical sensors for detection of substances dispersed or dissolved in gas or liquid environments. Several equivalent circuits exist for the QCM sensor. Design of these circuits depends mainly on an active layer of sensor as well as on an environment, in which a sensor is applied. An equivalent circuit is usually separated in two parts; the first one corresponds to quartz crystal, while the second part relates to chemical and physical properties, such as concentration of detected matter, viscosity of an active layer, viscosity of environment, etc.. For design of driven-oscillator circuit of QCM, it is necessary to develop accurate equivalent circuit, which is able to simulate behavior of QCM for a large range of concentration of detected matter. In the paper, the study is provided on polypyrrole-based QCM. Polypyrrole is suitable material for humidity measurements, and was deposited by matrix assisted pulsed laser evaporation technique in our case for two values of thicknesses. Electrical characteristics of polypyrrole-based QCM were measured for four concentrations of relative humidity. These experimental data are in good agreement with calculations based on our equivalent circuits. We can accurately simulate behavior of QCM in gas environment for various concentrations.

Quartz crystal microbalance belongs to a group of high-sensitive chemical sensors for detection of substances dispersed or dissolved in gas or liquid environments. Several equivalent circuits exist for the QCM sensor. Design of these circuits depends mainly on an active layer of sensor as well as on an environment, in which a sensor is applied. An equivalent circuit is usually separated in two parts; the first one corresponds to quartz crystal, while the second part relates to chemical and physical properties, such as concentration of detected matter, viscosity of an active layer, viscosity of environment, etc.. For design of driven-oscillator circuit of QCM, it is necessary to develop accurate equivalent circuit, which is able to simulate behavior of QCM for a large range of concentration of detected matter. In the paper, the study is provided on polypyrrole-based QCM. Polypyrrole is suitable material for humidity measurements, and was deposited by matrix assisted pulsed laser evaporation technique in our case for two values of thicknesses. Electrical characteristics of polypyrrole-based QCM were measured for four concentrations of relative humidity. These experimental data are in good agreement with calculations based on our equivalent circuits. We can accurately simulate behavior of QCM in gas environment for various concentrations.

gas sesnsing, polypyrrole, humidity, quarzt crystal micorbalance

gas sesnsing, polypyrrole, humidity, quarzt crystal micorbalance

VONDRA, M.; SEDLÁK, P.; SEDLÁKOVÁ, V.; MAJZNER, J.; ŠIKULA, J.; HOLCMAN, V.

2013

18.09.2012

Lubljana Slovenia

978-961-92933-2-4

MIDEM Society for Microelectronic, Electronic Components and Materials - Conference 2012 Proceedings

405

409

5