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With the advent of IoT and micro-packaging technology, the increasing number of wearable and portable electronics presents significant challenges for battery charging and replacement. To cope with the problem, energy harvesting technologies are drawing attention. Among them, triboelectric nanogenerator is of particular interest due to its advantage of high voltage output and lightweight, straightforward design. These advantages led to extensive research in the field of portable TENG. In spite of various attempts to enhance the performance of these portable TENGs, more fundamental approaches to overcome the limitations imposed by their small size are still needed. Herein, body-coupled energy harvesting triboelectric nanogenerator, BEH-TENG is introduced which can enhance the performance of energy harvesting of portable human-driven TENGs by harvesting an additional energy source. BEH-TENG can harvest conventional triboelectric energy from the device and triboelectric energy generated in between human body and ground simultaneously, which is body-coupled energy, transferred through human body. The mechanism of BEH-TENG is applied to jump rope and has undergone optimization with various parameters. BEH-TENG harvested two energy sources successfully with a minimum offset which generated a root-mean-square power of 59.98 μW and charged a 100 μF capacitor to 1.78 V for 100 s to power commercial thermohydrometer.

In the triboelectric nanogenerator (TENG) field, an innovative output enhancement strategy toward the ampere (A)-level and a broad design guideline to realize this strategy remain elusive. Herein, we propose self-enhanced electrostatic discharge triboelectric nanogenerator (SED-TENG) that has a simple design and mechanism to achieve ultrahigh current output performance. The SED-TENG based on the proposed synergistic effect between unidirectional charge accumulation and direct electron flow generated a peak voltage of approximately 2200 V, peak current of 7 A, and transferred charge of 50 μC in one cycle. The SED-TENG was optimized in terms of various design variables and circuit configurations by quantitatively comparing its peak and RMS outputs. The electrical output of the SED-TENG was investigated in various operating environments and under diverse conditions. Under a broad range of load resistances, the SED-TENG exhibited outstanding instantaneous and average output power characteristics. The SED-TENG can be utilized as ultrahigh performance energy harvesting tile, for example, the artificial grass-integrated SED-TENG generated stable outputs during walking and running. As practical applications, the SED-TENG was able to brightly illuminate 3000 LEDs and 56 W/108 W commercial fluorescent lamps, continuously operate three commercial sensor arrays without a time limit, furthermore, produce hydrogen/oxygen via water splitting.

The triboelectric nanogenerator (TENG) is an innovative technology that converts ambient mechanical energy into electricity based on electrostatic induction and triboelectrification. However, the TENG has an inherent critical problem of low peak and root mean square (RMS) output current due to its high internal impedance. Herein, we propose a unidirectional charge-supplying flutter TENG (UCSF-TENG), which exhibits highly enhanced peak/RMS current output performance. By leveraging just one rectifier diode and distinctive fluttering device design, the UCSF-TENG achieved a peak current of 5.9 A and an RMS current of 20 mA. The electrical output generation mechanism of the UCSF-TENG was systemically analyzed based on the mechanical fluttering motion analysis using a high-speed camera. In addition, the UCSF-TENG was structurally optimized via mechanical and electrical analyses for various design factors, through which it achieved an average power of 109 mW. Benefiting from such high output performance, the UCSF-TENG can successfully charge a supercapacitor of 0.22 F, power 108-W commercial lamps, and operate 12 commercial sensor arrays continuously. This work provides a promising strategy for boosting the output current performance of the TENG while maintaining integrability and portability.