Papers by Keyword: SAW Sensor

Abstract: When detecting torque with surface acoustic wave (SAW) resonator sensors, the real strain of the host structure is not exactly consistent with the strain of SAW resonator due to material mismatch and the finite-thickness adhesive problem. A 3-layer (host structure, adhesive, and resonator layer) model is established. Finite-element Analysis (FEA) was used to investigate the strain transfer from the metal substrate to the SAW resonator (SAWR) through a bonding layer. The results show that the values of the strain transfer rate of FEA agree well with the experimental data. It can be concluded that FEA is of great value for SAW sensor design and sensing applications.

Abstract: This paper presents new effective approachs for the supermolecule film deposition of surface acoustic wave (SAW) chemical sensors for detecting DMMP. 25-(thioalkyl-alkoxy)-p-tertbutylcalix [4] arene self-assembly molecular imprinted film as the sensitive film was coated on the gold delay line of SAW sensors to detect DMMP. The sensor has special response to organoosphorus compounds and the respond characteristic property in different temperatures of SAW sensor was studied in detail, had important reference value in counter-terrorism.

Abstract: It's not easy to achieve high-precision and wide range for the SAW temperature sensor. The multi-reflector reuse method is proposed in this paper based on the SAW delay-line theory. A pair of RF pulse query signals with difference query width are sent sequentially to the novel SAW sensor in a query period, the phase different of the RF pulse echo signal is analyzed based on the position factor. The novel method is used in the SAW sensor design, the SAW sensor can achieve the high accuracy and the well range at the same time.

Abstract: This study issues the improvement of the parameters of manufacturing on the flexible SAW device. The better piezoelectric characteristics of ZnO film will be obtained. The Sol-Gel method is used to prepare the ZnO solution and deposits ZnO film by spin coating process. X-ray diffraction (XRD) and scanning electron microscope (SEM) are used to get the crystalline property. The results reveal that ZnO film possesses better crystalline property in 400RPM of spin speed. The piezoelectric intensity of (002) direction is 1566.67 (a.u.) and atomic morphology of ZnO film are exhibited by SEM image. This better ZnO film will enhance the wave propagation of surface acoustic wave (SAW) device. It can also expand the application of SAW device.

Abstract: Detection of hydrogen gas is a crucial task for establishing safety and reliability of fuel cells, a key technology for the environment and our society. However, hydrogen is difficult to detect and various hydrogen sensors have many drawbacks. Here we report a novel hydrogen gas sensor, the ball surface acoustic wave (SAW) sensor, using Pd or PdNi sensitive film. The ball SAW sensor is based on a novel phenomenon, diffraction-free propagation of collimated beam along an equator of sphere. The resultant ultra-multiple roundtrips of SAW makes it possible to achieve highest sensitivity among SAW sensors. Moreover, it enables to use a very thin sensitive film, and consequently the shortest response time (2s) was realized. In terms of the sensing range, it has the widest range of 10 ppm to 100 % among any hydrogen sensors including FET or resistivity sensors. The ball SAW sensor can be applied not only to hydrogen but also to any gasses and possibly to liquids.