Flexible piezoresistive sensor matrix based on a carbon nanotube PDMS composite for dynamic pressure distribution measurement

A highly flexible, piezoresistive sensor matrix based on a carbon nanotube (CNT) polymer composite is developed for pressure distribution measurement applications. With an overall height of about 400 mu m, the sensors can measure pressure directly, without any deformation elements, such as a cantilever or a deformation membrane. The measurement range is from 2.5 to 640 kPa. Both the position and the pressure of the applied load can be measured and visualized as a resistance change. The relative resistance measurement deviation of the data acquisition system is lower than 3 % for the resistance range of 610 Omega to 380 k Omega. This corresponds to a systematic deviation of pressure measurement of less than 3 % in the measurement range. Besides the measurement of pressure, different sizes of loads can be detected as well. The developed fast and compact measurement system allows dynamic pressure measurement, such as gait analysis when used in an insole application.