Near-zero nonlinear error pressure sensor based on piezoresistor sensitivity matching for wind tunnel pressure test

Area of Science:

• Sensor Technology
• Materials Science
• Aerospace Engineering

Background:

• High-precision piezoresistive pressure sensors are vital in aerospace and automotive industries.
• Nonlinear error is a primary limitation in achieving higher sensor precision.

Purpose of the Study:

• To establish a mathematical model for evaluating nonlinear error in piezoresistive pressure sensors.
• To propose and verify a piezoresistor sensitivity matching method for suppressing nonlinear error.

Main Methods:

• Developed a mathematical model to quantify nonlinear error.
• Implemented a sensitivity matching technique by adjusting piezoresistor structure and position.
• Fabricated sensor prototypes using Micro-Electro-Mechanical Systems (MEMS) technology.

Main Results:

• Achieved theoretical quasi-zero nonlinear error through optimized piezoresistor sensitivity.
• Fabricated sensor prototypes demonstrated a nonlinear error as low as ±0.004%FS.
• Tested sensor prototypes in a Mach 4 wind tunnel with a measurement error of ±0.98%.

Conclusions:

• The proposed method effectively suppresses nonlinear error in high-precision piezoresistive pressure sensors.
• The developed sensor exhibits excellent performance metrics, including high sensitivity and low drift.
• This technology is crucial for high-precision surface pressure analysis in aircraft.