Design and Application of a High-G Piezoresistive Acceleration Sensor for High-Impact Application

Area of Science:

• Materials Science
• Mechanical Engineering
• Electrical Engineering

Background:

• High-g accelerations require specialized sensors for accurate measurement.
• Silicon-on-insulator (SOI) technology offers advantages for micro-electro-mechanical systems (MEMS) fabrication.

Purpose of the Study:

• To design, simulate, and manufacture novel SOI-based MEMS piezoresistive sensors capable of measuring accelerations up to 60,000 g.
• To validate the sensor's performance against a reference system under high-g conditions.

Main Methods:

• Development of a double-clamped beam structure with integrated piezoresistors.
• Utilizing a finite element method (FEM) simulation for optimizing beam length and sensor sensitivity.
• Fabrication of the sensor with specific pn-junction geometry (14 μm × 1.8 μm) and Wheatstone bridge configuration.

Main Results:

• The fabricated high-g sensor element has a compact geometry of 3 × 2 × 1 mm³.
• Sensor performance was validated using a shock wave bar and a Polytec vibrometer.
• The sensor accurately tracked acceleration waveforms up to 60,000 g, closely matching the reference laser signal.

Conclusions:

• The developed SOI-based MEMS piezoresistive sensor demonstrates high accuracy and reliability for measuring extreme accelerations.
• Potential applications include aerospace, impact detection, and control systems requiring high-g measurement capabilities.