A Bulk Acoustic Wave Strain Sensor for Near-Field Passive Wireless Sensing

Area of Science:

• Materials Science
• Electrical Engineering
• Mechanical Engineering

Background:

• Near-field passive wireless sensors are crucial for non-contact strain measurement in structural health monitoring.
• Existing sensors face challenges with stability and limited wireless sensing range.

Purpose of the Study:

• To present a novel bulk acoustic wave (BAW) passive wireless strain sensor.
• To enhance stability and extend the wireless sensing distance for structural health monitoring applications.

Main Methods:

• Developed a BAW passive wireless sensor using two coils and a quartz wafer.
• Utilized a double-mass-spring-damper model to analyze quartz-housing interaction.
• Employed a lumped parameter model to assess contact force influence on sensor signals.

Main Results:

• Achieved a sensitivity of 4 Hz/με at a 10 cm wireless sensing distance.
• Demonstrated resonant frequency independence from the coupling coefficient, reducing misalignment errors.
• Highlighted the sensor's high stability and modest sensing distance.

Conclusions:

• The developed BAW passive wireless strain sensor offers improved performance over existing technologies.
• Its stability and sensing range make it compatible with UAV-based monitoring platforms for large structures.
• This sensor advances non-contact strain measurement capabilities in structural health monitoring.