Newton's cradle motion-like triboelectric nanogenerator to enhance energy recycle efficiency by utilizing elastic deformation

Triboelectric nanogenerators (TENG) that harvest energy from ambient environment have attracted great attention since they were first reported. However, the structures of TENGs working in the vertical contact-separation mode are considerably monotonous and energy loss cannot be avoided during the working process. In this study, we design a novel TENG, which is based on three elastic plates and one acryl board in the center with two identical steel plates on both sides, using which periodic contact/separation of the friction layers proceeds like Newton's cradle, except for the intermittent input of mechanical energy to overcome the electrostatic interaction on the charged friction layers. Such a lamination structure in the original contact mode can provide considerably higher energy conversion efficiency than that of the friction layers in the original separation mode. With this new design, the output current of the TENG is 5.7 times as much as that of a common contact/separation TENG and 2.3 times as much as that of a similar structure TENG without the use of elasticity. The maximum short-circuit current, open-circuit voltage and output power are 114 mu A, 428 V, and 4.32 W m(-2), respectively, which are strong enough to light more than one hundred commercial LED lights. In addition, the TENG was applied to a self-powered flashing clapping palm decorated by 29 LEDs, which might replace the fluorescence palms that are powered by the chemical reactions of a dye mixed solution, in the future.