Design And Application Of Surface Acoustic Wave Liquid Sensor

Surface Acoustic Wave(SAW) sensor is a newly developed sensor which offers a great advantage of rapid, sensitive, real-time detection without high cost. It is widely used in environmental surveillance, chemical process control and clinic analysis. This dissertation reported on the development of SAW sensor and developed a 36°-YX LiTaO3 Shear-Horizontal Surface Acoustic Wave (SH-SAW) Liquid Detecting Sensor System based on monocrystalline silicon substrate, which has already successfully applied in real-time automated surveillance of heavy metal ion in sea water.Modem microelectronic and instrumental fabrication teclinique is used in the whole detecting system, which contains the high frequency detecting circuit, DSP micro processor and continuous-flow injection-itomic absorption system. This detecting system is designed to be sensitive, stable, repeatable, convenient, with small volume(30x20x20cm3) and good anti-interference technique. It is specially designed for real-time liquid electro-chemical detection.After the surface is plated with an Au layer together with protain A immobilization technique on the surface, the sensor can also be used in immune detection.