A High-Performance Micro Differential Pressure Sensor.

Area of Science:

• Microelectromechanical Systems (MEMS)
• Biomedical Engineering
• Sensor Technology

Background:

• Micro differential pressure sensors (MDPSs) are crucial for MEMS applications.
• Miniaturized sensors are essential for advanced biomedical catheters, especially in low-French (Fr) applications.
• Existing sensors often face challenges in meeting the stringent size and performance requirements for devices like 5Fr central venous pressure (CVP) monitoring catheters.

Purpose of the Study:

• To design and fabricate a high-performance, miniaturized silicon-on-insulator (SOI)-based MDPS for micro-pressure detection.
• To evaluate the sensor's performance characteristics, including sensitivity, nonlinearity, accuracy, and thermal stability.
• To assess the potential of the developed MDPS for integration into biomedical catheters.

Main Methods:

• Design and fabrication of an SOI-based MDPS using an 8-inch MEMS process.
• Characterization of the sensor's performance within a 0-1 kPa pressure range at room temperature and elevated temperatures up to 160 °C.
• Evaluation of key performance metrics: sensitivity, nonlinearity, accuracy, temperature coefficient of zero output (TCO), and temperature coefficient of sensitivity (TCS).

Main Results:

• The fabricated MDPS measures 1 mm × 1 mm × 0.4 mm.
• Achieved a sensitivity of 3.401 mV/V/kPa, nonlinearity of 0.376% FS, and overall accuracy of 0.59% FS at room temperature.
• Demonstrated stable operation up to 160 °C with TCO of 0.093% FS/°C and TCS of -0.144% FS/°C.

Conclusions:

• The miniaturized SOI-based MDPS meets the demanding size and performance criteria for integration into biomedical catheters.
• The sensor's high accuracy, sensitivity, and thermal stability make it suitable for critical applications like CVP monitoring.
• The use of a standard 8-inch MEMS process ensures cost-effectiveness for mass production, paving the way for wider adoption in medical devices.