A mapped conductive network model on the simulation of aligned CNT/PDMS flexible pressure sensor piezoresistivity

The piezoresistive sensitivity of aligned carbon nanotube (CNT)-elastomeric nanocomposites is investigated using a mapped conductive network model on finite element simulation. The study aims to investigate the sensor’s geometrical parameters, including shape and thickness, to enhance sensitivity under compressive load for applications requiring accurate pressure measurements. Substrates with different thicknesses and shapes are compressed to obtain the most efficient sensor structure including square, rectangular, and circular diaphragms. The developed strain field in the sensor as a result of indenter penetrating or uniform compressive pressure leads to the resistance change. The pertained resistivity to each maximum principal strain state is used directly from the conductive network model. The results disclose a good agreement with experimental data denoting improved sensitivity through bending of thinner sensors with square substrate. Results also reveal a decreased sensitivity for the rectangular indented substrates compared square substrates caused by more concentrated strain distribution during square substrate indentation.