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1D graphene based flexible sensors as wearable electronics have recently attracted considerable attentions because of lightweight, high extensibility, easy to wind and weave, and superior sensitivity. In this research, we established a facile and low-cost strategy to construct graphene thin film enabled yarn sensors (GYS) by combining the process of graphene oxide (GO) coating and reducing on polyester (PE) wound spandex yarns. According to systematic processing-property relationship study, a key finding of this work discovers that the degree of resistance recovery as well as gauge sensitivity of GYS can be well controlled and modulated by a pre-stretch treatment. Specifically, as the level of pre-stretch increases from 0 to 60%, the deformable range of sensor that guarantees full resistance recovery prolongs evidently from 0% to ~50%. Meanwhile, the gauge factor of GYS is tunable in the range from 6.40 to 12.06. To understand the pre-stretch process dependent sensing performance, SEM analysis was assisted to evidence the growing size of micro-cracks determining dominantly the behavior of electron transport. Lastly, to take better advantage of GYS, a new wearing mode was demonstrated by direct winding the yarn sensor on varied portions of human body for monitoring different body movements and muscle contracting & relaxing.

Macroscopic 3D graphene has become a significant topic for satisfying the continuously upgraded smart structures and devices. Compared with liquid assembling and catalytic templating methods, laser‐induced graphene (LIG) is showing facile and scalable advantages but still faces limited sizes and geometries by using template induction or on‐site lay‐up strategies. In this work, a new LIG protocol is developed for facile stacking and shaping 3D LIG macrostructures by laminating layers of LIG papers (LIGPs) with combined resin infiltration and hot pressing. Specifically, the constructed 3D LIGP composites (LIGP‐C) are compatible with large area, high thickness, and customizable flat or curved shapes. Additionally, systematic research is explored for investigating critical processing parameters on tuning its multifunctional properties. As the laminated layers are stacked from 1 to 10, it is discovered that piezoresistivity (i.e., gauge factor) of LIGP‐C dramatically reflects an ≈3900% improvement from 0.39 to 15.7 while mechanical and electrical properties maintain simultaneously at the highest levels, attributed to the formation of densely packed fusion layers. Along with excellent durability for resisting multiple harsh environments, a sensor‐array system with 5 × 5 LIGP‐C elements is finally demonstrated on fiber‐reinforced polymeric composites for accurate strain mapping.