Flexible Electronics Research Center, School of Mechanical Science and Engineering , Huazhong University of Science and Technology , Wuhan , Hubei 430074 , P. R. China.
Department of Materials Science , Fudan University , Shanghai 200433 , China.
ACS Appl Mater Interfaces. 2019 Feb 27;11(8):8567-8575. doi: 10.1021/acsami.8b21836. Epub 2019 Feb 15.
Electrically conductive composites (ECCs) hold great promise in stretchable electronics because of their printability, facile preparation, elasticity, and possibility for large-area fabrication. A high conductivity at steady state and during mechanical deformation is a critical property for ECCs, and extensive efforts have been made to improve the conductivity. However, most of those approaches are exclusively functional to a specific polymer matrix, restricting their capability to meet other requirements, such as mechanical, adhesive, and thermomechanical properties. Here, we report a generic approach to prepare ECCs with conductivity close to that of bulk metals and maintain their conductivity during stretching. This approach iodizes the surfactants on the commercial silver flakes, and subsequent photo exposure converts these silver iodide nanoparticles to silver nanoparticles. The ECCs based on silver nanoparticle-covered silver flakes exhibit high conductivity because of the removal of insulating surfactants as well as the enhanced contact between flakes. The treatment of silver flakes is independent of the polymer matrix and provides the flexibility in matrix selection. In the development of stretchable interconnects, ECCs can be prepared with the same polymer as the substrate to ensure strong adhesion between interconnects and the substrate. For the fabrication of on-skin electrodes, a polymer matrix of low modulus can be selected to enhance conformal contact with the skin for reduced impedance.
导电复合材料（ECCs）由于其可印刷性、制备简便性、弹性和大面积制造的可能性，在可拉伸电子产品中具有很大的应用前景。在机械变形过程中保持稳定状态的高导电性是 ECCs 的关键特性，因此已经进行了广泛的努力来提高其导电性。然而，大多数方法仅限于特定的聚合物基体，限制了它们满足其他要求的能力，例如机械、粘附和热机械性能。在这里，我们报告了一种通用的方法来制备导电性接近块状金属的 ECCs，并在拉伸过程中保持其导电性。该方法对商业银片上的表面活性剂进行碘化，随后进行光暴露将这些碘化银纳米颗粒转化为银纳米颗粒。基于银纳米颗粒覆盖银片的 ECCs 由于去除了绝缘表面活性剂以及片材之间接触增强而表现出高导电性。银片的处理与聚合物基体无关，为基体选择提供了灵活性。在可拉伸互连的开发中，可以使用与基底相同的聚合物来制备 ECCs，以确保互连与基底之间的强粘附力。对于皮肤电极的制造，可以选择具有低模量的聚合物基体，以增强与皮肤的共形接触，从而降低阻抗。
