Chinese ink enabled natural wood for moist-induced electricity generation

Moist-induced electricity generators (MEGs) that harvest electric energy from water or moist has been considered as an efficient and sustainable technique to meet the increasingly serious energy crisis. However, the low output performance, non-degradability and complicated preparation processes of current MEGs have hindered their practical application. Herein, we report a highly-efficient, green and easily fabricated wood-derived moist-induced electricity generator (WMEG) by simply soaking natural wood in the Chinese ink. The generated electricity based on streaming potential comes from when water molecules flow through the charged channel surface of ink-coated wood driven by capillary force and evaporation. As a result, a continuous open-circuit voltage of about 250 mV was achieved from a single WMEG under ambient conditions, and the electrical signal could maintain stale for over 72 h. Moreover, the power output performance of the obtained wood generator can be enhanced by simple series or parallel connection for practical applications, and an electronic calculator can be powered by six-series-connected devices. This current study provides insights for the development of low-cost and sustainable MEGs without complex chemical reaction.