| Title |
Development of Batteryless SAW-based Integrated Microsensor and Wireless Measurement Technique |
| Authors |
오해관(Oh, Hae-Kwan) ; 김태현(Kim, Tae-Hyun) ; 왕웬(Wang, Wen) ; 양상식(Yang, Sang-Sik) ; 이기근(Lee, Kee-Keun) |
| Keywords |
표면탄성파 ; 유한요소법 Surface Acoustic Wave(SAW) ; Temperature Sensor ; Pressure Sensor ; RFID Tag ; Coupling of Modes(COM) ; Finite Element Methods |
| Abstract |
We developed a 440MHz surface acoustic wave (SAW) microsensor integrated with pressure-temperature sensors and ID tag. Two piezoelectric substrates were bonded, in which ~150 μm cavity was structured. Four sides were completely sealed by JSR photoresist (PR). Pressure sensor was placed on the top substrate, whereas ill tag and temperature sensor were placed on the bottom substrate. Using network analyzer, the developed microsensor was wirelessly tested. Sharp reflection peaks with high S/N ratio, small signal attenuation, and small spurious peaks were observed. All the reflection peaks were well matched with the coupling of mode (COM) simulation results. With a 10mW RF power from the network analyzer, a ~1 meter readout distance was observed. Eight sharp ON reflection peaks were observed for ID tag. Temperature sensor was characterized from 20°C to 200°C. A large phase shift per unit temperature change was observed. The evaluated sensitivity was ~10°/°C. |