论文部分内容阅读
证明了SAW延迟线振荡器的谐振频率对淀积在延迟线表面上的有机薄膜很敏感。理论指出SAW器件对质量负载的灵敏度取决于谐振频率的平方。用谐振频率为31,51和112MHz涂有严格控制成分及厚度的有机膜的器件对这个关系进行了实验研究。若器件用上合适的吸附性涂层,可将SAW振荡器的质量灵敏度用于制造非常灵敏的化学传感器。从工作频率为290MHz的SAW延迟线振荡器(是迄今所报道过的最高频率的SAW化学传感器)得到的结果表明,要对浓度大体低于1×10~(-4)(以体积计)的有机气体进行快速探测是容易办到的。
It is proved that the resonant frequency of the SAW delay line oscillator is sensitive to the organic thin film deposited on the surface of the delay line. The theory states that the SAW device’s sensitivity to mass loading depends on the square of the resonant frequency. This relationship was experimentally studied with devices with organic films with strictly controlled composition and thickness at 31, 51, and 112 MHz resonant frequencies. The SAW oscillator’s mass sensitivity can be used to make very sensitive chemical sensors if the device is coated with a suitable adsorptive coating. The results obtained from a SAW delay line oscillator operating at 290 MHz, the highest frequency SAW chemical sensor hitherto reported, indicate that for a concentration of less than 1 × 10 -4 (by volume) Organic gas for rapid detection is easy to do.