Preparation and properties of flexible conductive polydimethylsiloxane composites containing hybrid fillers

Aiming to fabricate highly flexible conductors via a facile method, hybrid fillers of carbon nanotubes (CNTs) and carbon fiber (CF) were incorporated with polydimethylsiloxane (PDMS) using a solution blending method. The results showed that the hybrid fillers evidently decreased the composite resistivity and the lowest resistivity was achieved with the composite that had 6:4 CNT/CF ratio when the total filler content was 1 wt%. Due to the low filler content, the stretching strains of the composites reached greater than 200%, and the conductive network which was formed by flexible CNT and rigid CF was sensitive to strain and the related resistance change of resulted composites reached 2480.5% with a gauge factor of 50. The alternating current electrical, rheological and morphological property measurements were performed, and the results presented the existence of synergistic effect between the hybrid fillers in the conductive networks which decreased resistivity of composites. Therefore, the PDMS/CNT/CF nanocomposites are good candidates for application as inflexible sensors.