Design And Application Of Multiplex Phase And Amplitude Detector For Acoustic Wave Sensors

With the development of surface acoustic wave technology, surface acoustic wave devices have been widely used in various fields, especially in the field of biological detection. They have got a wide range of applications and continuous development due to their high sensitivity and low detection limit. This paper presents a kind of love wave sensor together with a phase and amplitude detection instrument which can complete the detection of multiplex sensors at the same time. This instrument can detect specific markers of lung cancer in the exhaled breath condensate and the detection limit can reach ppb level. This paper also initially completed the test of love wave cell sensor using in the detection of toxin.The content of this article is divided into three parts: The first part is the design of the sensor. Firstly, designed a love wave sensor specially used in the liquid environment, the sensitivity of which can reach 1.2080/ng. Secondly, designed the microfluidic chip which can match the sensor well.The second part is the design of hardware, including the passage for liquid and the test circuit. Carefully chose the injection pump and made the sensor base and the detection interface. The signal source is based on direct digital synthesizer chip AD9954 and the detection circuit is based on chip AD8302. The analog multiplexer switch also takes part to achieve a high-throughput detection. The storage and control system is based on the MSP430 chip. The second part also includes the design of software. Designed the program in MSP430 which can control the flow of liquid and complete the collection, storage and transmission of data. Also designed the PC program, which can specifically control the steps of experiment and the parameters. It can also display the real-time data on the screen and other functions such as filtering and the drawing of standard curve.The third part is the experimental verification of the instrument. In the detection of exhaled breath condensate, the standard curve whose linearity is over 0.95 is obtained by the phase detection of a series of standard samples. And the actual samples are also successfully detected. In the toxin detecting experiment, the standard curve whose linearity is over 0.9 is obtained by the amplitude detection.