基于超支化聚合物的声表面波化学毒剂传感器

基于声表面波（SAW）技术的化学毒剂传感器在检测下限、响应速度以及减小温度、湿度交叉敏感等方面还需进一步提高。提出了在SAW双端口谐振器上涂敷超支化聚合物的方法提高传感器的检测下限和灵敏度。通过建立Van Dyke模型，分析了敏感膜对SAW化学毒剂传感器Q值、插入损耗以及电路阻抗匹配的影响。利用谐振器代替延迟线，确保了器件具有插入损耗、高Q值的特点。实验证实，在谐振器的中心栅结构上涂覆聚合物可以减小粘弹性聚合物对谐振器插损、Q值以及输入输出阻抗的影响。对设计的化学毒剂传感器进行了沙林毒剂检测实验，采用315MHz的SAW谐振器结合超支化聚合物膜，检测沙林气体浓度为5．0mg／m^3。实验表明：这种传感器的灵敏度可达到600Hz／mg／m^3，响应时间为50s，恢复时间约为60s。

Chemical toxic agents sensor based on surface acoustic wave resonator with hyperbranched polymer membrane

Gas sensor based on surface acoustic wave(SAW) technology is needed to be improved in the detection limit,the response time and the reduction of temperature and humidity sensitivity.A dual-port SAW resonator coated with hyperbranched polymer membrane is introduced.By the establishment of Van Dyke model,the impacts of the sensitive polymer membrane on Q-value and insertion loss of chemical agent sensor as well as on circuit impedance matching are analyzed.Meanwhile,research is done to find out the impact of the location of membrane coating on the device,and the experiment result shows that coating on the center grating between interdigital transducers(IDT) has relatively best effects.The design and features of hyperbranched polymer are also introduced.Experiments are done on the sensor.By exposed to Sarin agent of 5.0 mg/m3,a 315 MHz dual-port SAW resonator coated with hyperbranched polymer membrane is applied.Experiments show that the sensitivity of the sensor can be achieved 600 Hz/mg/m3,the response time is 50 s,and recovery time is about 60 s.