Optimal Design of a Polyaniline-Coated Surface Acoustic Wave Based Humidity Sensor

Sensors

Wen Wang¹  Xiao Xie² 

[1] State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, No.21, BeiSiHuan West Road, Beijing, China;

关键词: Al/Au electrodes;    COM model;    humidity sensor;    oscillator;    polyaniline;    resonator;   

DOI  :  10.3390/s131216816

来源: mdpi

【 摘 要 】

This paper presents an optimal design for a new humidity sensor composed of a dual-resonator oscillator configuration with an operation frequency of 300 MHz, and a polyaniline (PANI) coating deposited along the resonation cavity of the sensing device. To improve the corrosion resistance of the sensor chip, Al/Au electrodes were used to form the SAW resonator. Prior to device fabrication, the coupling of modes (COM) model was used for the performance prediction and optimal design parameters determination. Two SAW resonators with Al/Au electrodes were fabricated on an ST-X quartz substrate, and used as the frequency control element in the feedback path of an oscillator circuit. A PANI thin coating was deposited onto the resonator cavity of the sensing device by a spinning approach as the sensor material for relative humidity (RH) detection. High detection sensitivity, quick response, good repeatability and stability were observed from the sensor experiments at room temperature.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.