A₂-Mode Lamb Passive-Wireless Surface-Acoustic-Wave Micro-Pressure Sensor Based on Cantilever Beam Structure

Area of Science:

• Materials Science and Engineering
• Sensor Technology
• Microelectromechanical Systems (MEMS)

Background:

• Passive-wireless surface-acoustic-wave (SAW) sensors are crucial for extreme environments but lack sensitivity at low pressures.
• Conventional SAW sensors face performance limitations as measured pressure decreases.

Purpose of the Study:

• To enhance the sensitivity of SAW micro-pressure sensors for low-pressure applications.
• To introduce an A2-mode Lamb SAW sensor with an integrated inertial structure.

Main Methods:

• Utilized an A2-mode Lamb SAW sensor combined with a cantilever beam inertial structure.
• Employed a MEMS-compatible process for fabricating a multi-layer SiO2/AlN/SOI structure.
• Established a dedicated micro-pressure testing system for performance evaluation.

Main Results:

• The proposed SAW micro-pressure sensor demonstrated significantly enhanced sensitivity.
• Experimental validation confirmed the sensor's high responsiveness to micro-pressure variations.
• The integrated inertial structure effectively improved low-pressure detection.

Conclusions:

• The A2-mode Lamb SAW sensor with a cantilever beam inertial structure offers a viable solution for high-sensitivity micro-pressure sensing.
• The MEMS-compatible fabrication process is effective for producing these advanced sensors.
• The design proves effective for applications requiring precise low-pressure measurements in challenging conditions.