Regulating the electro-dielectric architectures of carbon black-engineered polyester fibers and fabrics for strain sensing and microwave absorption

With the advent of next-generation high-frequency wireless electronic sensors, signal interference between sensors become severe. Integrating the sensor and microwave absorber is highly needed, but challenges remain in a single-component material due to the contradiction between electrical conductivity and dielectric properties. Here, a one-step surface sizing of polyester fibers (PET) and coating of carbon black (CB) using styrene-acrylic emulsion (SAE) as sizing regent was proposed to produce multifunctional fibers (PET-SAE/C) continuously. This approach endows the fibers with balanced electrical conductivity and dielectric properties, making them a promising material for strain sensors and microwave absorbers. The obtained PET-SAE/C fibers exhibit remarkable sensitivity to the resistance changes over 1000 cycles of strain-sensing treatment. Simultaneously, the PET-SAE/C fibers had strong microwave absorption properties with a minimum reflection loss (RL_min) of −67.82 dB at a predicted thickness of 2.28 mm. The fibers were successfully weaved into 3D fabrics, which retained outstanding strain sensing and microwave absorption performance, the RL_min approached −62.87 dB at the thickness of 2.28 mm. This study provides insights into creating flexible, efficient, and multifunctional fiber and fabric materials for integrating strain sensors and microwave absorbers in versatile wireless electronics.