Based On The Surface Of Saw Devices Slit Inter-atomic Forces Monitoring Sensor Research And Design

For the objects in thin gap, it is very important to monitor the contact pressurebetween the surfaces of two touching objects. The corresponding measurement resultsnot only provide reference for safe operation, but also validate the theoretical model.Up to now, there are piezoelectric, piezoresistive, capacitive, inductive and opticalsensors for contact pressure measurement,but they are all wired based operation with aseparate power supply, which is inconvient or impossible for contact pressuremeasurement in thin gap.However,wireless passive SAW sensing technology provides anew clue to monitor the stress in thin gap.Based on wireless passive SAW sensing technology, SAW sensing schemes for thecontact pressure monitoring in thin gap is proposed. According to the analytical modelsof the SAW sensor, the corresponding wireless passive SAW contact pressure sensor isdesigned theoretically. The main contents are listed as follows:1. For the indirect SAW sensing scheme, the impedance contact pressure sensor isinvestigated principally; for the direct SAW sensing scheme, the force sensitivestructure is suggested.Then,Comparison of the scheme for the contact pressuremonitoring in thin gap is performed and direct SAW sensing scheme is preferable.Thecorresponding sensor is direct resonant SAW sensor in ZnO multilayered structure.2. The micro-manufacturing processes of the direct resonant SAW contactpressure sensor in ZnO multilayered structure are initially presented,which include theprocesses of single crystal silicon lapping, ZnO piezoelectric film deposition, thefabrication of SAW resonator and sensor packaging,etc.3. According to the analytical models of the SAW sensor, the design of the directresonant SAW contact pressure sensor in ZnO multilayered structure is performed. Thedesign includes the analysis of the SAW propagation property, the caculation of thetemperature and contact pressure sensitivity coefficients and the design of the one portSAW resonator in the multilayered piezoelectric media.