Strain sensors for smart wearable textiles have recently attracted great attention due to their potential in the healthcare applications, specifically, functions to track heartbeat, pulse signals, and movements of limbs and joints. Traditional methods typically require complicated procedures including dip-coating in different solutions to prepare sensing fibers before weaving into fabrics. In this study, we used an ultraviolet picosecond laser to directly induce graphene on polyimide (PI) fabric to produce a strain sensor. The process is mask-free, easy-to-fabricate, and the graphene tracks are well-adhered to the substrate. High-quality 3D-porous graphene was produced directly using appropriate laser parameters with a sheet resistance as low as 20 Ω/sq. The graphene strain sensors showed high sensitivity within a small strain range (strain below 4%) (GF_max = 27), good linearity, a low threshold value (strain = 0.08%), and high stability (4% resistance loss after 1000 cycles). Furthermore, reliable signals gathered from various human motions demonstrated the potential for health-care monitoring.

中文翻译：

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通过石墨烯直接激光写入在纺织品上稳定的可穿戴应变传感器

用于智能可穿戴纺织品的应变传感器由于其在医疗保健应用中的潜力，最近引起了极大的关注，特别是具有跟踪心跳，脉搏信号以及四肢和关节运动的功能。传统方法通常需要复杂的过程，包括在不同溶液中浸涂以在织入织物之前制备传感纤维。在这项研究中，我们使用紫外线皮秒激光在聚酰亚胺（PI）织物上直接诱导石墨烯以产生应变传感器。该工艺无掩模，易于制造，并且石墨烯轨迹良好地粘附到基板上。使用合适的激光参数直接生产出高质量的3D多孔石墨烯，其薄层电阻低至20Ω/ sq。_max = 27），良好的线性度，较低的阈值（应变= 0.08％）和较高的稳定性（1000次循环后电阻损耗为4％）。此外，从各种人体运动中收集到的可靠信号证明了医疗保健监测的潜力。