Abstract Conductive silicon rubbers (CSRs) are potential candidates for strain sensor application owing to their specific electrical response and superior mechanical flexibility. In this work, carbon fiber-filled CSRs were printed by an extrusion device. Thixotropic agent was added to modify mobility and viscosity of the liquid CSR. It was found that the CSR with 5 wt% thixotropic agent addition exhibited better shape-retention. Fibers in matrix were observed to be oriented in the printing direction resulting in an anisotropic electrical and mechanical behavior. The printed CSRs showed better electrical and mechanical properties along the orientation direction of fibers. In particular, the volume resistivity at the orientation direction was 6.8 times lower than that at perpendicular direction. Higher tensile strength, larger elongation at break, and higher Young's modulus were found along the orientation direction when the printed CSRs were stretched, where a large number of fibers were pulled out and visible holes remained at the fractured surface. Electrical responses of the CSRs under various loadings, including stretching, compressing, bending, twisting and cyclic folding, were closely related with deformations of the CSRs. Sandwich strain sensors were finally fabricated to verify a practical application as motion sensor of the printed CSRs.

中文翻译：

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碳纤维填充导电硅橡胶的3D打印

摘要 导电硅橡胶 (CSR) 由于其特定的电响应和优异的机械柔韧性而成为应变传感器应用的潜在候选者。在这项工作中，碳纤维填充的 CSR 是通过挤出设备打印的。添加触变剂以改变液体 CSR 的流动性和粘度。发现添加 5wt% 触变剂的 CSR 表现出更好的形状保持性。观察到基质中的纤维在印刷方向上取向，导致各向异性的电气和机械行为。印刷的 CSR 沿着纤维的取向方向显示出更好的电气和机械性能。特别是，取向方向的体积电阻率比垂直方向的体积电阻率低 6.8 倍。更高的拉伸强度，更大的断裂伸长率，当拉伸印刷的 CSR 时，沿取向方向发现更高的杨氏模量，其中大量纤维被拉出，断裂表面保留可见孔。CSRs在拉伸、压缩、弯曲、扭曲和循环折叠等各种载荷下的电响应与CSRs的变形密切相关。最后制作了三明治应变传感器，以验证作为印刷 CSR 运动传感器的实际应用。与 CSR 的变形密切相关。最后制作了三明治应变传感器，以验证作为印刷 CSR 运动传感器的实际应用。与 CSR 的变形密切相关。最后制作了三明治应变传感器，以验证作为印刷 CSR 运动传感器的实际应用。