Fabrication and Characteristics Investigation of Large Strain Composite Based on the Super Flexible Matrix

The PDMS/MWNTs (polydimethylsiloxane/multi-walled carbon nanotubes) composite large strain sensitive materials were prepared by the physical blending technology, and the effect of the proportion on the large strain sensing properties was investigated. The sensing mechanism model was established based on the microstructures characterization. The large strain properties of PDMS composite material filled with MWNTs and graphite were preliminary explored. The results show that the PDMS/MWNTs composite material exhibits the good linear characteristic between the relative resistance rate and the large strain:the optimal strain property with the strain coefficient 3.1 can be obtained when the content of MWNTs is 9 wt%. The resistance change of the PDMS/MWNTs/graphite composite materials exhibits the nonlinear characteristics with the large strain. The analysis reveals that the mutual complementation of the remote conductive network of MWNTs and short-range conductive network of graphite forms the more stable conductive pathways and network, so as to retard the linear increase of resistance.