Miura folding based charge-excitation triboelectric nanogenerator for portable power supply

Miniaturized mobile electronic devices have aroused great attention due to their convenience to daily life. However, they still face a problem that power supply from the conventional cell needs to be regularly charged or replaced. Portable electricity supply collecting energy from environment is highly desired. Herein, a highly flexible and stretchable Miura folding based triboelectric nanogenerator (MF-TENG) is prepared by using flexible polyethylene terephthalate (PET) as a folding substrate with a double working side design, specifically one side as the main TENG (M-TENG) and other side as the excitation TENG (E-TENG). The E-TENG supplements charge to M-TENG by a half-wave rectifier circuit. This design increases the TENG working area and reduces its volume. The output performance of the TENG based on Miura folding with charge excitation called MF-CE-TENG is greatly boosted. The optimal output charge and maximum peak power of MF-CE-TENG achieves 1.54 µC and 5.17 mW at 1 Hz, respectively, which is 4.61 and 10.55 times as much as that of MF-TENG without charge excitation. To demonstrate its applications, the MF-CE-TENG is used to light up 456 LEDs brightly and charge a 100 µF capacitor to 6.07 V in 5 min. A calculator and a temperature-humidity sensor work normally powered by MF-CE-TENG with an energy management module. This work provides a new strategy to enhance the output energy of Miura folding TENG by applying a charge excitation mode for the first time, which might be an effective approach to be used in other TENGs.