A High-Performance Micro Differential Pressure Sensor

With the development of the micro electromechanical system (MEMS), which widely adopts micro differential pressure sensors (MDPSs), the demand for high-performance MDPSs had continuously increased. Pressure sensors realized using MEMS technology integrated with biomedical catheters are of significant importance in the detection and treatment of various biological diseases. Biomedical catheters used in low-Fr applications (1Fr = 0.33 mm outer diameter) require miniaturized sensors that do not compromise their performance. For instance, catheters (5Fr) used for central venous pressure (CVP) monitoring require the integration of high-performance sensors with total dimensions smaller than 1.65 mm along at least two directions (length, width, or height). In this paper, a silicon-on-insulator (SOI)-based MDPS was designed and fabricated for micro-pressure detection in the range of 0-1 kPa. The dimension of the sensor is only 1 mm x 1 mm x 0.4 mm, with a sensitivity of 3.401 mV/V/kPa at room temperature, nonlinearity of 0.376% FS (full scale), and an overall accuracy of 0.59% FS. The sensor operates normally when the temperature is even increased to 160 degrees C, and its temperature coefficient of zero output (TCO) and temperature coefficient of sensitivity (TCS) are 0.093% FS/degrees C and -0.144% FS/degrees C. The dimension and performance results of this MDPS demonstrate its potential to play a significant role in biomedical catheters. In addition, it is fabricated using an 8-inch MEMS process, which significantly reduces the cost.