Triboelectric Nanogenerator Based on Human Hair

Triboelectric nanogenerators (TENGs) can be incorporated into modern electronic devices requiring sustainable, renewable, and reliable microscale energy sources. We report the first use of human hair, which is known to be a highly triboelectric material, for the fabrication of biobased TENGs. Ethanolic NaOH was used to dissolve hair, and two simple fabrication techniques, bar- and spin-coating methods, were used to prepare hair-based films on electrode substrates. The dissolved hair paste has somewhat different chemical composition from original hair, but the hair-based film has almost the same level as the untreated human hair in the triboelectric series. The spin-coated film is thinner and has more even surface compared with the bar-coated one, and exhibits better performance in triboelectric generation. The TENG using a spin-coated hair film produced the maximum peak-to-peak voltage of 103 V and the power density of 60 mW m(-2) across a 1.2 M Omega resistor; using the TENG device, an array of LEDs was in situ lighted without the aid of energy-collecting capacitors. A biowaste human hair offers the advantage of easy accessibility and processability into a highly tribopositive material for TENGs, and our work thus broadens the choice of positive tribo-materials and offers a novel approach for fabricating cost-effective, high efficiency, and biobased TENGs.