Super high sensitive plate acoustic wave humidity sensor based on graphene oxide film

• Published in: Ultrasonics 2017-11, Vol.81, p.135-139
• Main Authors: Kuznetsova, Iren E., Anisimkin, Vladimir I., Gubin, Sergei P., Tkachev, Sergei V., Kolesov, Vladimir V., Kashin, Vadim V., Zaitsev, Boris D., Shikhabudinov, Alexander M., Verona, Enrico, Sun, Shaorong
• Format: Article
• Language: English
• ISSN: 0041-624X; 1874-9968
• DOI: 10.1016/j.ultras.2017.06.019

•The super high sensitive plate acoustic wave humidity sensor with sensitive graphene oxide film was developed.•The operation threshold of the sensor is equal to 0.03% RH.•Water vapor leads to decreasing elastic modules and to increasing thickness of the graphene oxide film. The changes of density and elastic modules due to water vapor adsorption are measured for graphene oxide film at room temperature. Dominant mechanism for acoustic wave humidity sensing by the film is shown to be related with variation of its electric conductivity. Basing on the data, super high sensitive humidity sensor employing high-order Lamb wave with large coupling constant, standard lithium niobate plate, and graphene oxide sorbent film is developed. The minimal detectable level of the sensor is as low 0.03% RH, response times are 60/120s, and reproducibility is ±2.5%. The sensor is completely selective towards H2, CO, CH4, NO, O2.