High-Performance Film Bulk Acoustic Wave Pressure and Temperature Sensors

Abstract

A film bulk acoustic wave resonator (FBAR)-based sensor for the simultaneous measurement of temperature and pressure with high sensitivity is fabricated and characterized. Temperature or pressure sensing is determined by the change in the series resonant frequency of the FBAR device when exposed to a measurement environment. For temperature sensing, measurement results show a sensitivity of 25.02 ppm/ C, a nonlinearity less than AE0:005% over the measurement range of 10 to 80 C, and a hysteresis within AE0:005% in one temperature cycle. In pressure sensing, measured results show a sensitivity of 336.2 ppm/ bar, a nonlinearity less than AE0:004% over the measurement pressure range of 0 to 2.07 bar, and a hysteresis within AE0:007% in one pressure cycle.

Frequency response of AlN-based solidly mounted resonators under mechanical stress

“…Hence, for each kind of device and particular use, the response to a given stress has to be individually analysed. Pressure sensors based on film bulk acoustic resonators (FBAR) [2,3], Lamb wave resonators [4], and thin film surface acous-tic wave (SAW) resonators [5,9] have been reported previously. Strain sensors, intended for harsh environments or requiring high response speed (i.e.…”

Tilted $c$-Axis Thin-Film Bulk Wave Resonant Pressure Sensors With Improved Sensitivity

“…COUSTIC waves in thin film plates are expected to exhibit high pressure sensitivity due to the plate large aspect ratio [1]. Further, acoustic resonators exhibit low noise performance which in turn provides the possibility to achieve high measurement resolutions.…”

“…To this end FBARs with both c-textured and c-tilted AlN thin films, respectively have been studied. It is noted that FBARs are chosen as test devices here because of their excellent properties regarding gravimetric and pressure sensitivity [1,3] as well as the one dimensional nature of the vibration mode, which in turn allows straightforward interpretation of the pressure sensitivity.…”

Wireless temperature sensing using a passive RFID tag with film bulk acoustic resonator

“…Mass sensors, temperature sensors, gas sensors, chemical sensors, humidity sensors, pressure sensors and bio sensors utilizing acoustic wave devices have been reported. [1][2][3][4][5][6] Here, the focus is on the temperature sensing by using FBAR resonators.…”