Performance Investigation of Carbon Nanotube Based Temperature Compensated Piezoresistive Pressure Sensor

In silicon-based piezoresistive pressure sensor, the accuracy of the sensor is affected mainly by thermal drift and the sensitivity of the sensor varies with the rise in temperature. Here, the temperature effects on the desired representation of the sensor are analysed. Use of smart material Carbon nanotubes (CNT) and a few effective temperature compensation techniques are presented in this study to reduce the temperature effect on the accuracy of the sensor. Resistive compensation employed extra piezoresistors with Negative Temperature Coefficient of Resistivity (TCR) for temperature compensation. The attainment of the desired compensation techniques is highly compatible with the MEMS device fabrication. The compensated pressure sensor is supremacy for pressure measurement with temperature variations. Though various techniques have been suggested and put into actuality with successful attainment, the techniques featuring easy implementation and perfect compatibility with existing schemes are still blooming demanded to design a piezoresistive pressure sensor with perfect comprehensive performance. In this paper, CNT piezoresistive material has been employed as sensing elements for pressure sensor and compared with silicon in terms of output voltage and sensor performance degradation at higher temperature. Pressure sensors using CNT and silicon piezo resistive sensing materials were simulated on silicon (100) diaphragm by ANYSIS. Based on simulation results, silicon and CNT both pressure sensor also shows better results at near room temperature. With the increasing temperature it is observed that silicon pressure output underestimated by 23%.