A kind of methane sensor based on the principle of piezoelectricity is developed.The PANI/PdO composite thin film is fabricated by chemical oxidative polymerization of aniline with PdO nanoparticles

and the PANI/PdO thin films which is sensitive to methane is fabricated through layer-by-layer self-assembly method.The film is deposited on the piezoelectric material by sputtering.It accomplishes the detection of CH4 by the absorption of CH4 which can change the oscillation frequency of the piezoelectric crystal.The experimental results show that the sensor has good selectivity.And the output of the sensor has good linear relationship with the volume fraction range of CH4 0 %

2

%.