Monolithic Piezoelectric Sensor Array System For Liquid Phase

Piezoelectric crystal sensor is a kind of detection device which has advantages of broad spectrum,high sensitivity simple structure and low cost,especially it is widely used as quality based sensor in gas phase analysis.With successful oscillation in the liquid phase,the application of piezoelectric quartz crystal sensor has been involved in many fields,such as analytical chemistry,surface chemistry,biochemistry and environmental monitoring.In many of the piezoelectric crystals,quartz crystal is widely used as a sensor transducer with excellent physical and chemical properties.a specific membrane is prepared on the crystal surface which is specific binding of target objects in the determinand to be measured.whit the quality-frequency transforming relationship of the quartz crystal,the quality and concentration signals can be converted into frequency signal output,in order to realize the detection of quality and concentration.With the rapid development of the material science,more and more piezoelectric materials have have been researched,among which langasite crystal is regarded as the substitute of quartz crystal because of its better performance compared with quartz crystal.considering the research of langasite crystal has been researched at home and abroad,this paper chose langasite and quartz crystal as core core component at the same time.In recent years,the research of array,integrated and intelligent is an important development direction of piezoelectric sensor.A novel monolithic array piezoelectric sensor measuring system is designed and fabricated,which can be used in liquid phase detection.Five electrode units are fabricated on a single piezoelectric chip which are used in the form of plastic packaging.The operation mode of the five pairs of electrodes are controlled by a single chip microcomputer to eliminate the common interference factors during the measurement.Phase locked loop circuit and transformer branch circuit is used to compensate for the inevitable parallel capacitor,which is used to improve the vibration performance of the crystal,and to make it work in series resonant frequency.The developed test system is used for the detection of Salmonella,and has a good test result.