Besides the unique advantages of high sensitivity, small size, low power consumption, and strong mechanical stability, the driving factor for developing CNTs-based pressure sensor is the thermal stability. Unlike the conventional Si-based pressure sensors which have maximum operating temperature of 120°C, CNT based pressure sensor can be operated up to 250°C. Based on the piezoresistive effect, when the aligned multi-walled carbon nanotube (CNT) array is compressed, individual carbon nanotubes start to buckle, which in turn decreases the array's electrical resistance. This behavior was found to be almost fully recoverable for the loading of up to 500 g. The change in the resistance increases linearly when 100 g and 500 g load were applied at a temperature of 20°C to 180°C. Thus MWCNTs array promises to be a very effective sensing element for pressure and strain sensor operating at elevated temperature.