Triboelectric nanogenerators (TENGs), particularly those with high flexibility and sophisticated geometry, have shown great application foreground in portable and wearable electronics. However, traditional fabrication approaches remain complicated and non-versatile, which are also impractical in the preparation of complex shapes and structures. Herein, a one-pot coaxial direct ink writing (DIW) 3D printing technique has been proposed to fabricate a fully flexible single-electrode TENG (FFTENG) with sophisticated shapes and 3D structures for the purpose of harvesting and utilizing biomechanical energy. This FFTENG is made up of a silicone elastomer shell as the triboelectric layer and an inner silicone/carbon black (CB) core as the flexible electrode. Various factors that affect the output electric performance, including the ratio of the inner and outer diameter of the printed fiber, CB content, loading frequency, applied contact force, specimen size, and external load resistance, are investigated in detail via the contact-separation test. The results show that a standard square FFTENG with a size of 30 × 30 mm² can yield an open-circuit voltage (V_oc), a short-circuit current (I_sc) and a short-circuit transferred charge (Q_sc) of as high as 60 V, 0.23 μA and 58 nC, respectively, and a maximum output peak power density of 15.59 mW m⁻² at a matched resistance of 80 MΩ. More importantly, various shape-adaptable FFTENGs can be designed and tailored to meet the diverse needs of different applications, such as self-powered LED systems, self-charging power systems, LED control devices, self-powered tactile sensors, flexible self-monitoring grip exercisers, and flexible self-powered keyboards, and open up new avenues for use in multifunctional self-powered electronic systems, including biomechanical energy harvesting and utilization, self-powered sensing and human-machine interaction.

摩擦纳米发电机（TENGs），特别是那些具有高柔性和复杂几何形状的发电机，在便携式和可穿戴电子产品中显示出巨大的应用前景。然而，传统的制造方法仍然复杂且通用，这在复杂形状和结构的制备中也不切实际。在此，提出了一种一锅同轴直接墨水书写（DIW）3D打印技术来制造具有复杂形状和3D结构的完全柔性单电极TENG（FFTENG），以收集和利用生物力学能量。该 FFTENG 由作为摩擦电层的有机硅弹性体壳和作为柔性电极的内部有机硅/炭黑 (CB) 核组成。影响输出电气性能的各种因素，包括印刷纤维的内外径比、CB含量、加载频率、施加的接触力、试样尺寸和外部负载阻力，通过接触分离试验进行了详细研究。结果表明，一个尺寸为 30 × 30 mm 的标准正方形 FFTENG²可以产生分别高达 60 V、0.23 μA 和 58 nC的开路电压 ( V _oc )、短路电流 ( I _sc ) 和短路转移电荷 ( Q _sc )，以及最大输出峰值功率密度为 15.59 mW m ^-2匹配电阻为 80 MΩ。更重要的是，可以设计和定制各种形状适应性强的 FFTENG，以满足不同应用的多样化需求，例如自供电 LED 系统、自充电电源系统、LED 控制装置、自供电触觉传感器、灵活的自监控握力训练器和灵活的自供电键盘，并为多功能自供电电子系统开辟了新的途径，包括生物力学能量收集和利用、自供电传感和人机交互。