以128°YX—LiNbO3晶体上实现的双声路声表面波(SAW)器件为载体,在器件的测量声路上制作了对SO2气体具有敏感作用的碳纳米管聚苯胺薄膜,提出了一种基于碳纳米管聚苯胺薄膜的SAWSO2气体传感器。该传感器中的双声路结构消除了因外界测量条件改变引起的测量误差,提高了传感器的可靠性和准确性。利用原位法制备的碳纳米管聚苯胺增加了SO2气体的吸附面积,提高了传感器的灵敏度。实验结果表明,基于碳纳米管聚苯胺薄膜的SAWSO2气体传感器在测量范围内对各种浓度的SO2气体具有好的响应特性;当输入体积分数为1×10^-6时,传感器的响应灵敏度约为8.3kHz,比单一聚苯胺薄膜高1.8kHz。此外,该传感器也具有更好的线性特件。
A novel scheme of surface acoustic wave (SAW) SO2 gas sensor based on the carbon nanotube-polyanilin films is proposed. The carbon nanotube-polyanilin films are fabricated on the measure acoustic track of surface acoustic wave device on 128°YX-LiNbO3 crystals. Because the dual track receiving structure is incorporated into the sensor, the measurement errors caused by the environmental disturbance are eliminated, and the reliability and accuracy are further improved. The carbon nanotube-polyanilin films prepared by the in-situ polymerization can increase the absorb area of SO2 gas, and sensor sensitivity is improved. Experimental results confirm that the surface acoustic wave SO2 gas sensor based on carbon nanotube-polyanilin films is endowed to excellent response performance. When SO2 gas injected is 1×10^-6 , the sensitivity reaches to 8. 3 kHz in measurement range, about 1.8 kHz higher than the sensor with only polyanilin films. Furthermore, the sensor has better linearity sensitivity compared with the sensor with only polyanilin films.