An electroacoustic chemical sensor based on thin-film bulk acoustic wave resonators (TFBAR) is presented. It operates on the same principle of the well-known quartz crystal micro-balance, at an operation frequency extended up to several GHz. The larger output signal, associated to the higher operation frequency, is a condition to improve the device sensitivity. TFBARs have been implemented on (001) Si wafers, using Si3 N4 AlN membranes, obtained by anisotropic etching of Si. Time response and calibration curves have been tested on TFBAR sensors exploiting two different chemically interactive membranes: Pd and Co-tetra-phenyl-porphyrin, both deposited in the form of thin-films by thermal evaporation. Measurements performed upon exposure to H2, CO, and ethanol have shown the ability of the device to detect low concentrations of the analyte with a fast and repeatable response.
Microbalance chemical sensor based on thin-film bulk acoustic wave resonators
M Benetti;F Di Pietrantonio;V Foglietti;E Verona
2005
Abstract
An electroacoustic chemical sensor based on thin-film bulk acoustic wave resonators (TFBAR) is presented. It operates on the same principle of the well-known quartz crystal micro-balance, at an operation frequency extended up to several GHz. The larger output signal, associated to the higher operation frequency, is a condition to improve the device sensitivity. TFBARs have been implemented on (001) Si wafers, using Si3 N4 AlN membranes, obtained by anisotropic etching of Si. Time response and calibration curves have been tested on TFBAR sensors exploiting two different chemically interactive membranes: Pd and Co-tetra-phenyl-porphyrin, both deposited in the form of thin-films by thermal evaporation. Measurements performed upon exposure to H2, CO, and ethanol have shown the ability of the device to detect low concentrations of the analyte with a fast and repeatable response.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
