Penciling a triboelectric power source on paper

We present a novel triboelectric nanogenerator (TENG) based on a paper-Teflon configuration fabricated by an easy and cost-efficient process. Carbon electrodes were hand-drawn by means of a graphite pencil on commercial paper cards, and the conductivity was confirmed by multimeter. In order to increase the effective triboelectric area, we used sandpaper imprinting to increase the surface roughness more than 2-fold compared to flat surfaces yielding a more than 6-fold enhancement of power density. The achieved output voltage, current and power density were ~55 V, ~2.5 μA and ~17 μW/cm2, respectively. The arch-shaped TENG shows robust output power when pressed by fingers to power a 2-bit liquid crystal display (LCD) demonstrating its use as energy harvester based on low-cost, commodity materials such as paper, Teflon and graphite.