A New Surface Acoustic Wave Temperature Sensor Device Designed by the Institute of Acoustics

2024-02-29

The thermal radiation loss caused by high temperature environment can cause significant acoustic attenuation in sensor devices. Therefore, sensors operating in this environment should have a sufficiently large quality factor (Q) and low loss. Traditional wired active sensors cannot be used for temperature measurement in high-temperature environments, while wireless passive temperature sensors based on surface acoustic wave (SAW) provide a good solution for this.

Li Xueling, a doctoral student in the Ultrasonic Technology Center of the Institute of Acoustics, Chinese Academy of Sciences, and his supervisor Wang Wen, etc., used the short pulse method to extract accurate reflection coefficients, and used the typical coupling modes (COM) model to optimize the design of LGS/Pt structure surface acoustic wave temperature sensor device. Simulation and experiment proved that the device has good high-temperature sensing performance. The relevant research results are published online in Sensors.

Researchers conducted experimental studies on the structure of LGS/Pt devices with different Pt film thicknesses and wavelength ratios. Researchers used the small multiplication method to fit the experimental data and obtained a formula for calculating the reflection coefficient. They used the finite element method to extract other COM parameters of Pt/LGS, simulated the single port resonator of Pt/LGS structure using a typical COM model, and determined the design parameters with larger Q values.

Researchers used photolithography technology to develop a 400MHz single port surface acoustic wave resonator, and measured it with a network analyzer to obtain a high Q value. The measurement results were in good agreement with the simulation results. The high-temperature characteristics of the prepared sensing device were tested in the temperature range of 50-650 ℃, and the test results showed good stability and linear TCF (~25 ppm/° C), proving that the device has good high-temperature sensing performance.

Research has shown that surface acoustic wave high-temperature sensing technology can be used for high-sensitivity temperature monitoring and early warning in high-temperature environments.

The research work has been supported by projects such as the National Natural Science Foundation of China Joint Key Fund.

Vulnerabilities in the new IoT basic module or posing security risks to a large number of devices