两相碳填料型压力敏感复合导电材料中协同导电效应的量化研究

With the conductive composites deeply applied in the field of pressure-sensitive robot skin, the pressure-sensitive conductive composites filled with carbon materials of two types which have a good overall performance are gradually used to make the robot skin. However, lacking the quantitative equation for the synergistic conductive effect of the pressure-sensitive conductive composites filled with carbon materials of two types, currently, it is hard to quantify the transmission characteristic of the pressure-sensitive conductive composites filled with carbon materials of two types. Therefore, we will design pressure-sensitive conductive rubber filled with graphene and carbon black with high mechanical reproducibility and high electrical stability, will, taking the general effective media theory, the seepage volume fraction and seepage coefficient of graphene and carbon black into consideration, build the equation for calculating the resistivity of the pressure-sensitive conductive composites filled with graphene and carbon black, and then clarify the quantitative features on the synergistic conductive effect of the pressure-sensitive conductive composites filled with carbon materials of two types. This research can reveal the inherent relationship between the characteristic parameters of filler and the static parameters of sensitive material, can be applied to build the transfer function of pressure sensor based on such materials, can provide a theoretical basis and technical support for enhancing the static characteristics of pressure-sensitive composites filled with carbon materials of two types, and can further expand the application scope of conductive composites in the field of pressure-sensitive robot skin.

随着复合导电材料在压力敏感机器人皮肤领域的深入应用，综合性能良好的两相碳材料填充型复合导电材料逐渐用于制作压力敏感机器人皮肤。由于目前两相碳填料型复合导电材料中协同导电效应的定量计算未有效开展，致使两相碳填料型压力敏感复合导电材料的传输特性难以量化，本研究拟设计具有高力学重复性和高电学稳定性的压力敏感石墨烯/炭黑/硅橡胶复合导电材料体系，结合通用有效介质方程以及石墨烯、炭黑的渗流体积分数和渗流系数，构建并验证石墨烯/炭黑/硅橡胶压力敏感复合导电材料的电阻率计算模型，阐明两相碳填料型压力敏感复合导电材料中协同导电效应的定量特征。研究成果能够揭示填料特征参数与敏感材料静态特性参数的内在关联，用于构建基于此类材料的压力传感器传输函数，为提升两相碳填料型压力敏感复合导电材料的静态特性指标提供理论依据和技术支撑，进一步拓展复合导电材料在压力敏感机器人皮肤领域的应用范围。

随着复合导电材料在压力敏感机器人皮肤领域的深入应用，综合性能良好的两相碳材料填充型复合导电材料逐渐用于制作压力敏感机器人皮肤。本工作针对两相碳填料型复合导电材料中协同导电效应的定量计算进行研究，取得如下研究成果：① 根据复合导电高分子材料的粘弹性理论，得出基体-基体、基体-填料、填料-填料之间的相互作用是影响压力敏感复合导电材料力学网络重复性和电学网络稳定性的关键因素。② 构建得到基于通用有效介质理论的导电炭黑/橡胶电阻-压力计算模型，将导电炭黑/橡胶材料的电阻与填料关键参数有效结合，分析了基于此类压力敏感材料的传感器静态特性。随着导电填料体积分数的增大，复合导电材料的电阻率从渗流区向传导区转变，工作原理从压阻效应向应变效应转变。③ 填料并用时不同填料之间存在显著的“协同导电效应”，由于填料在制备过程中无法做到某一参数完全一致，很难定量分析填料的物理/化学参数对复合材料导电效应的影响。因此，采用基于蒙特卡洛模拟的计算机仿真技术分析填充料连接的可能概率，进而估计复合导电材料的电渗流特性。该方法不受材料制备工艺和参数的影响，能连续设置填料的尺寸，既可以观察单一填料的体积分数和尺寸对复合导电材料电渗流阈值的影响，还可以从多相填料的体积分数和尺寸出发，对各种连续组份下协同导电效应进行仿真。结合蒙特卡洛模拟和实验，构建得到两相碳填料型压力敏感复合导电材料的协同导电效应的理论公式。研究所得成果为提升基于压力敏感复合导电材料的传感器性能提供理论依据和技术支撑，进一步拓展复合导电材料在压力敏感机器人皮肤领域的应用范围。