Capacitive pressure sensors based on microstructured polymer-derived SiCN ceramics for high-temperature applications

Area of Science:

• Materials Science
• Sensor Technology
• Ceramic Engineering

Background:

• Traditional silicon-based pressure sensors lack sensitivity and temperature resistance for extreme environments.
• High-temperature pressure monitoring is crucial in industries like aerospace and energy.

Purpose of the Study:

• To develop and characterize a novel capacitive pressure sensor using polymer-derived SiCN ceramics.
• To evaluate the sensor's performance at high temperatures (up to 500°C) and varying pressures.

Main Methods:

• Fabrication of SiCN ceramic capacitive pressure sensors with convex microstructures using a sample replication strategy.
• Performance testing under pressures ranging from 0-800 kPa at temperatures from room temperature to 500°C.
• Analysis of sensor parameters including sensitivity, non-linearity, hysteresis, and repeatability.

Main Results:

• The SiCN ceramic sensor exhibited high sensitivity (0.197 pF/MPa) and low non-linearity (0.26%) at room temperature.
• Sensor performance showed no degradation at 500°C, maintaining high sensitivity (0.214 pF/MPa) and low non-linearity (0.24%).
• The sensor demonstrated excellent repeatability and low hysteresis across the tested temperature and pressure ranges.

Conclusions:

• SiCN ceramic capacitive pressure sensors offer superior high-temperature performance compared to traditional silicon sensors.
• The inherent properties of SiCN ceramics, such as oxidation/corrosion resistance and thermal stability, make them ideal for harsh environments.
• These sensors show significant potential for reliable pressure acquisition in high-temperature and demanding industrial applications.