P1.2.12 Uncoated PZT thick film cantilever for chemical species detection in gaseous phase
- Event
- 14th International Meeting on Chemical Sensors - IMCS 2012
2012-05-20 - 2012-05-23
Nürnberg/Nuremberg, Germany - Chapter
- P1.2 Resonant Sensors
- Author(s)
- R. Lakhmi, H. Debéda, C. Lucat - University of Bordeaux, Laboratoire IMS (France)
- Pages
- 923 - 926
- DOI
- 10.5162/IMCS2012/P1.2.12
- ISBN
- 978-3-9813484-2-2
- Price
- free
Abstract
Coated silicon cantilevers functioning with flexural mode are classically used for chemical species detection. Recently, new types of entirely screen-printed piezoelectric PZT cantilevers operated with the unusual "in-plane" 31-longitudinal mode have been shown to be good candidates for actuation, sensing or energy harvesting applications. In order to prevent from ageing phenomena linked to the sensitive layer, the cantilever sensors may be used without any coating. Detection of water and ethanol is successfully performed using the 31-longitudinal mode of uncoated PZT cantilever sensors giving respectively negative and positive frequency shifts. As the viscosity and density of those gases don't allow explanation of such high values of frequency shifts, responses have to be found in the competition between mass and stiffness effects. Differences between the cantilever's response to water and ethanol can be explained by the higher wettability of gold towards ethanol. Indeed, whereas the main effect of water onto the gold surface seems to be linked to mass effects, only stiffness effects can justify the positive shifts observed in the case of ethanol vapour.