采用物理共混工艺制备了聚二甲基硅氧烷/多壁碳纳米管(PDMS/MWNTs)复合大应变敏感材料，研究了掺杂比例对其大应变敏感特性的影响；在形貌表征基础上建立了敏感机理模型。初步探索了MWNTs和石墨填充PDMS复合材料的大应变特性。结果表明，PDMS/MWNTs复合材料相对电阻变化率与大应变成良好的线性特性，其中MWNTs掺量为9 wt%时复合材料表现出最优的应变特性，应变系数达到3.1；MWNTs和石墨填充PDMS复合材料电阻变化随大应变表现出非线性特性，分析认为MWNTs的远程导电网络和石墨的近程导电网络相互补充，搭建起更加稳定的导电通路，从而减缓了电阻的线性增大。%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.
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