Temperature-independent piezoresistive sensors based on carbon nanotube/polymer nanocomposite

Temperature-independent property and high piezoresistivity are critical for carbon nanotube polymer nanocomposites with sensing capability. In this work, a temperature-independent CNT/Epoxy resin nanocomposite was fabricated successfully. This composite has good and stable piezoresistivity between 233 K and 373 K. By developing a multi-scale percolation network model, this work also reveals theoretically the inherent mechanisms to obtain temperature-independent sensors. In order to fully consider the tube–tube and/or tube–matrix interaction in the composite, the structural distortion of nanotubes is determined self-consistently by minimizing the pseudo-potential energy and the thermally assisted tunneling transport is calculated by the Landauer-Büttiker formula. Simulation results show that temperature-independent composite with further improved piezoresistivity (gauge factor > 40) can be achieved by dispersing the treated and selected CNTs to the theoretically matched polymer matrix. These temperature-independent, highly sensitive, low cost and homogeneous sensors have a great potential for wide range applications, such as in electronic skin, man-machine interaction and body monitoring.