Stretchable sensors based on conductive polymer composites (CPCs) are attracting considerable interest from both academia and industry. For CPCs consist of elastomeric substrates with dispersed conductive fillers, a strain-induced conductivity-drop phenomenon (negative piezo-conductivity effect) is often observed in previous reported studies. Herein, CPCs with unconventional positive piezo-conductivity effect were prepared by employing a facile and low-cost fabrication process based on thermoplastic polyurethane (TPU) and conductive metal particles (nickel/iron particles). For the first time, a strongly stretch-induced conductive networks formation phenomenon was observed under tensile strain, contributing to the electrical resistivity of the composites decreases by more than 6 orders of magnitude under 20 % tensile strain. The evolution of conductive networks and resistivity under uniaxial strain were studied with scanning electron microscope (SEM) and a modified mathematic model, respectively. Furthermore, these CPCs exhibits temperature sensing capability between 30-60 ^oC, indicating such method could be used to fabricate multi-functional sensors.

基于导电聚合物复合材料（CPC）的可拉伸传感器引起了学术界和工业界的极大兴趣。对于CPCs由具有分散的导电填料的弹性体基底组成，在先前报道的研究中经常观察到应变引起的电导率下降现象（负压电导率效应）。在本文中，通过采用基于热塑性聚氨酯（TPU）和导电金属颗粒（镍/铁颗粒）的简便且低成本的制造工艺来制备具有非常规正压电导电效果的CPC。首次在拉伸应变下观察到强烈的拉伸诱导的导电网络形成现象，这导致复合材料的电阻率在20％拉伸应变下降低了6个数量级以上。用扫描电子显微镜（SEM）和改进的数学模型分别研究了单轴应变下导电网络的演化和电阻率。此外，这些CPC具有30-60的温度感应能力^o C，表明这种方法可用于制造多功能传感器。