Abstract Flexible sensors for large strain detection have recently been attracted the attention of researchers. This investigation reports a stretchable strain sensor in which carbon nanotubes (CNTs) were diffused into polydimethylsiloxane (PDMS) using a facile swelling/permeating method. The CNTs were further modified by using a silane coupling agent (SCA) to improve dispersion and the interaction between CNTs and PDMS. The CNTs permeated the skin layer of the PDMS composite and the inner core of PDMS contained few CNTs, forming a sandwich-like structure. The low CNTs content (0.48 wt%) and sandwich-like structure resulted in excellent composite flexibility which allowed work strains to exceed 350% and Young's modulus to increase from 0.25 MPa to 0.40 MPa. Surface modification of the CNTs improved their permeation depth and dispersion, which was shown to enhance composite sensitivity. The relative resistance change reached 4850% with a gauge factor of 20 by 1.0 wt% SCA modification. Cycled electromechanical properties showed a stable resistance response and sensitivity against strain. Therefore, the PDMS/CNTs nanocomposites prepared by swelling/permeating and CNTs surface modification in this study have various application potentials in the flexible sensor field.

中文翻译：

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基于聚二甲基硅氧烷/碳纳米管 (CNT) 的高柔性应变传感器通过溶胀/渗透方法制备，并通过 CNT 表面改性提高灵敏度

摘要 用于大应变检测的柔性传感器最近引起了研究人员的关注。本研究报告了一种可拉伸应变传感器，其中使用简便的溶胀/渗透方法将碳纳米管 (CNT) 扩散到聚二甲基硅氧烷 (PDMS) 中。通过使用硅烷偶联剂 (SCA) 进一步改性 CNT，以改善分散和 CNT 与 PDMS 之间的相互作用。碳纳米管渗透到聚二甲基硅氧烷复合材料的表层，聚二甲基硅氧烷的内核几乎不含碳纳米管，形成夹心状结构。低碳纳米管含量 (0.48 wt%) 和三明治状结构导致优异的复合柔韧性，允许工作应变超过 350%，杨氏模量从 0.25 MPa 增加到 0.40 MPa。碳纳米管的表面改性提高了它们的渗透深度和分散性，这被证明可以提高复合灵敏度。通过 1.0 wt% SCA 修改，相对电阻变化达到 4850%，应变系数为 20。循环机电特性显示出稳定的电阻响应和对应变的敏感性。因此，本研究中通过溶胀/渗透和CNTs表面改性制备的PDMS/CNTs纳米复合材料在柔性传感器领域具有多种应用潜力。