Pd+ ions (90 keV) were implanted at normal incidence and at room temperature in different highly insulating (>200 GΩ) thermoplastic polymers (poly(methyl methacrylate), polypropylene, polyethylene terephthalate glycol-modified, and polycarbonate). At high fluence and optimized process parameters, the ion implantation gives rise to the formation of a nanocomposite thin surface layer constituted by Pd nanoclusters and carbonaceous material (nanographite/amorphous carbon). The morphological, microstructural, and microanalytical properties of the nanocomposite layers were investigated by He-ion microscopy, glancing incidence X-ray diffraction, and Raman scattering, respectively. The electrical properties were characterized by resistance, van der Pauw, and Hall measurements. We performed accurate simultaneous deformation/bending experiments and electrical resistance measurements. We show that the electrical resistance varies linearly with the mechanical deformation (beam deflection) applied. The experimental results are interpreted by “hopping conductivity” model considering the nanostructure configuration of the nanocomposite layers. A gauge factor in the range between 4 and 8, depending on the ion-implanted polymer, was obtained for prototype strain gauge devices.

中文翻译：

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Pd+离子注入聚合物的应变特性

Pd+ 离子 (90 keV) 以垂直入射和室温注入不同的高绝缘 (>200 GΩ) 热塑性聚合物（聚（甲基丙烯酸甲酯）、聚丙烯、聚对苯二甲酸乙二醇酯、乙二醇改性和聚碳酸酯）。在高通量和优化的工艺参数下，离子注入会形成由 Pd 纳米团簇和碳质材料（纳米石墨/无定形碳）构成的纳米复合薄表面层。纳米复合材料层的形态、微观结构和微观分析性质分别通过 He 离子显微镜、掠入射 X 射线衍射和拉曼散射进行了研究。电特性通过电阻、范德堡和霍尔测量来表征。我们进行了精确的同步变形/弯曲实验和电阻测量。我们表明电阻随施加的机械变形（梁偏转）呈线性变化。考虑到纳米复合材料层的纳米结构配置，通过“跳跃电导率”模型来解释实验结果。对于原型应变仪装置，获得了介于 4 和 8 之间的应变系数，具体取决于离子注入聚合物。