Abstract
A novel wireless and passive surface acoustic wave (SAW) based temperature-compensated vibration sensor utilizing a flexible Y-cut quartz cantilever beam with a relatively substantial proof mass and two one-port resonators is developed. One resonator acts as the sensing device adjacent to the clamped end for maximum strain sensitivity, and the other one is used as the reference located on clamped end for temperature compensation for vibration sensor through the differential approach. Vibration directed to the proof mass flex the cantilever, inducing relative changes in the acoustic propagation characteristics of the SAW travelling along the sensing device, and generated output signal varies in frequency as a function of vibration. A theoretical mode using the Rayleigh method was established to determine the optimal dimensions of the cantilever beam. Coupling of Modes (COM) model was used to extract the optimal design parameters of the SAW devices prior to fabrication. The performance of the developed SAW sensor attached to an antenna towards applied vibration was evaluated wirelessly by using the precise vibration table, programmable incubator chamber, and reader unit. High vibration sensitivity of ∼10.4 kHz/g, good temperature stability, and excellent linearity were observed in the wireless measurements.
Highlights
In recent years, the surface acoustic wave (SAW) devices have gained increasing attraction for wireless sensing for temperature, pressure, chemical compositions, vapour, humidity, torque and others mechanical constraints [1,2,3,4,5,6,7]
A prototype of SAW based vibration sensor with beam structure was developed for electronic warning system, and it was composed of a piezoelectric ST-cut quartz cantilever beam with a SAW delay line pattern fabricated on top of the beam surface and an aggregated mass attached on undamped end of the beam
The present SAW vibration sensor still suffers from the poor temperature compensation, the active sensor structure makes the sensor is difficult for wireless vibration measurement in some extreme environments because of the power system
Summary
The surface acoustic wave (SAW) devices have gained increasing attraction for wireless sensing for temperature, pressure, chemical compositions, vapour, humidity, torque and others mechanical constraints [1,2,3,4,5,6,7]. The sensor signal is demodulated wirelessly by evaluating the differential frequency shifts of the reflected impulses utilizing the reader unit This sensor presents many advantages over other currently available vibration sensors: (1) it provides high sensitivity through optimal design by using the established theory model on response mechanism; (2) the temperature dependence is compensated effectively by using the differential structure; (3) the sensor chip is absolutely passive and does not require a battery or any power supply to operate; and (4) it is light, small, and can withstand extremely harsh environmental conditions. Using the precise vibration table, and programmable incubator chamber, the performance of the developed SAW based vibration sensor was evaluated in wireless measurement referring to the interrogation unit
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
