Nano-Crystalline SnO2 Thin Film Based Surface Acoustic Wave Sensor for Selective and Fast Detection of NO2 Gas

ABSTRACTThis work is related to designing, fabricating, and testing a surface acoustic wave sensor to be used for detecting metastable inert gases, particularly helium. The assembly consists of two microsensor configurations: (a) a reference device with no deposition at the delay line and (b) a sensing device with an Au-activated TiO2 e-beam-deposited thin film on the delay line. The interdigitated transducers and delay lines are fabricated by photolithography techniques on a single Y-cut LiNbo3 substrate oriented for Z-propagation of the acoustic waves. Variation in electrical conductivity of the Au-activated TiO2 film due to exposure to metastable He is translated as a frequency change in the assembly. Various characteristics of the surface acoustic microsensor have been studied to better understand and optimize the variation of acoustic wave velocity and the operating frequency of the microdevice. Methods for the TiO2 thin-film deposition are discussed.

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Theoretical and Experimental Investigation on the Use of a Surface Acoustic Wave Sensor for SU-8 Thin-Film Adhesion Characterization

IEEE Sensors Journal ◽

10.1109/jsen.2015.2426173 ◽

2015 ◽

Vol 15 (8) ◽

pp. 4667-4676

Author(s):

Mohamed M. EL Gowini ◽

Walied A. Moussa

Keyword(s):

Thin Film ◽

Experimental Investigation ◽

Acoustic Wave ◽

Surface Acoustic Wave ◽

Film Adhesion ◽

Acoustic Wave Sensor ◽

Thin Film Adhesion

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Aluminum Nitride Thin Film Based Surface Acoustic Wave Sensors

10.1557/proc-1139-gg03-47 ◽

2008 ◽

Author(s):

A. Kabulski ◽

V. R. Pagán ◽

D. Cortes ◽

R. Burda ◽

O. M. Mukdadi ◽

...

Keyword(s):

Thin Film ◽

Acoustic Wave ◽

Aluminum Nitride ◽

Surface Acoustic Wave ◽

Acoustic Wave Sensors ◽

Wave Sensors

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Investigation into surface acoustic wave sensor for DCM gas detection using COMSOL multiphysics

Ferroelectrics ◽

10.1080/00150193.2020.1868875 ◽

2021 ◽

Vol 572 (1) ◽

pp. 94-105

Author(s):

Mohamed Moustafa ◽

Ghaylen Laouini ◽

Mostafa ElNaggar ◽

Tariq AlZoubi

Keyword(s):

Acoustic Wave ◽

Surface Acoustic Wave ◽

Gas Detection ◽

Comsol Multiphysics ◽

Acoustic Wave Sensor

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Formation of a Complex Topologies of SAW-Based Inertial Sensors by Laser Thin Film Local Evaporation

Micromachines ◽

10.3390/mi12010010 ◽

2020 ◽

Vol 12 (1) ◽

pp. 10

Author(s):

Alexander Kukaev ◽

Dmitry Lukyanov ◽

Denis Mikhailenko ◽

Daniil Safronov ◽

Sergey Shevchenko ◽

...

Keyword(s):

Thin Film ◽

Acoustic Wave ◽

Surface Acoustic Wave ◽

Acoustic Waves ◽

Inertial Sensors ◽

Surface Acoustic Waves ◽

Sensing Element ◽

Small Series ◽

Evaporation Technique ◽

Photolithography Process

Originally, sensors based on surface acoustic waves are fabricated using photolithography, which becomes extremely expensive when a small series or even single elements are needed for the research. A laser thin film local evaporation technique is proposed to substitute the photolithography process in the production of surface acoustic wave based inertial sensors prototypes. To estimate its potential a prototype of a surface acoustic wave gyroscope sensing element was fabricated and tested. Its was shown that the frequency mismatch is no more than 1%, but dispersion of the wave on small inertial masses leads to a spurious parasitic signal on receiving electrodes. Possible ways of its neglecting is discussed.

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