A Miniature Layered SAW Contact Stress Sensor for Operation in Cramped Metallic Slits

作者：Li, Haining^*; Ding, Jiexiong; Wei, Siqi; Chu, Bowen; Guan, Lichao; Du, Li; Liu, Guangmin; He, Jianguo

来源：Instruments and Experimental Techniques, 2018, 61(4): 610-617.

DOI：10.1134/S0020441218040097

Based on passive and wireless surface acoustic wave (SAW) sensing technology, a sensor terminal was designed to measure the contact stress in a cramped metallic slit with less than 0.5 mm in width. A layered structure of force-sensitive element with 0.5 mm in total thickness was put forward to package SAW resonator. Thin films with elasticity and flexibility were adopted to transfer load effectively between rigid surfaces. A flexible transmission line with double-stub structure and a patch microstrip antenna were used to realize the wireless interrogation to the sensor. The force-sensitive element model was built and simulated with FEA software (COMSOL Multiphysics). The sensor prototype exhibited significant linear and repeatable frequency shifts for the loads in the range of 0-4 MPa. The linearity error was +/- 3% of full-scale output (FSO), and the accuracy was +/- 1.25% FSO. The usage of elastic films in force-sensitive element caused hysteresis in output, but the hysteresis error was controlled in an acceptable range of +/- 3.8% FSO.

• 出版日期2018-7
• 单位电子科技大学; 中国工程物理研究院