Facile fabrication and characterization of arch-shaped triboelectric nanogenerator with a graphite top electrode

We fabricated and characterized the polydimethylsiloxane (PDMS)-based triboelectric nanogenerators (TENGs) by employing a top electrode made of graphite. For a flexible electrode, the graphite was prepared on aluminum (Al) tape by a simple rolling pr∞ess. By pressing a roller on the Al tape attached to a graphite substrate, the graphite flakes were entirely coated on its glue side for the graphite top electrode. For fabricating the TENG, the micro-pillar patterned PDMS as a triboelectric material was laminated on an indium tin oxide (ITO) coated polyethylene terephthalate (PET) substrate as a bottom electrode. Under the external pushing forces of 0.1- 0.3 kgf, the measured open-circuit voltage (V∞) and short-circuit current (Isc) of the TENG with the graphite top electrode were improved compared to the TENG with the ITO top electrode due to the superior electrical property. For the TENG with the graphite top electrode, the averaged V∞ and Isc values were ∼1.80V and 120.4 nA, respectively, at a frequency of 1Hz (cf. V∞ ∼0.97V and Isc ∼69.3 nA for the TENG with the ITO top electrode). The effect of pushing frequency on the output performance of the fabricated TENG was also investigated.