This article investigates electrical conductivity and piezoresistivity of carbon nanotube (CNT)-polymer nanocomposites using an efficient analytical model. The effects of chopped carbon fibers on the electrical conductivity and percolation behavior of multiscale polymer-based nanocomposites containing CNTs are examined at various maximum angular orientations and different polymer matrix barrier heights. The multiscale nanocomposite (MSNC) electrical conductivity and percolation onset are found to be dependent on the carbon fiber and CNT geometry and dispersion. The tunneling effect is discussed as an important mechanism to explain the low percolation threshold and nonlinear electric behavior of MSNC. A comparison between nanocomposites filled with CNTs and MSNC reinforced with CNTs and chopped carbon fibers demonstrates different percolation behaviors. Moreover, the influences of CNT position and orientation changes on the piezoresistivity of polymer nanocomposites are studied. Resistance change ratio as a function of applied strain demonstrates a non-linear behavior due to tunneling resistance change between CNTs.

本文使用有效的分析模型研究碳纳米管（CNT）聚合物纳米复合材料的电导率和压阻。在各种最大角度取向和不同的聚合物基质阻隔高度下，研究了碳纤维短切对含碳纳米管的多尺度聚合物基纳米复合材料的电导率和渗透行为的影响。发现多尺度纳米复合材料（MSNC）的电导率和渗透开始取决于碳纤维和CNT的几何形状和分散度。隧道效应是解释MSNC低渗流阈值和非线性电行为的重要机制。碳纳米管填充的纳米复合材料与碳纳米管和短切碳纤维增强的MSNC的比较显示出不同的渗透行为。此外，研究了碳纳米管的位置和取向变化对聚合物纳米复合材料压阻的影响。电阻变化率与所施加应变的函数关系显示出非线性行为，这是由于CNT之间的隧穿电阻变化所致。