Harvesting Electricity from Water Evaporation through Microchannels of Natural Wood

• Published in: ACS applied materials & interfaces Vol. 12; no. 9; pp. 11232 - 11239
• Main Authors: Zhou, Xiaobing, Zhang, Wenluan, Zhang, Chenglin, Tan, Yao, Guo, Junchang, Sun, Zhengnan, Deng, Xu
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 04.03.2020
• Subjects: streaming potential/current; evaporation; electricity generation; natural wood; capillarity
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.9b23380

When external pressure drives an electrolyte solution in a capillary tube with a charged inner surface, we obtain a streaming potential/current. This effect is also manifested when water flows through the microchannels of a tree, which is driven by capillary pressure and natural evaporation. Thus, by making use of natural evaporation, we took advantage of the anisotropic three-dimensional wood structures to fabricate nanogenerators drawing electricity from the streaming potential/current. As a result, direct current can be harvested continuously, simply through a piece of wood. A 300 mV open-circuit voltage and a 10 μA short-circuit current (I SC) were recorded from a single device, which surpassed the I SC values of most previous works by an order. By connecting five wood nanogenerators in series, a calculator can be completely functional, as a demonstration for practical application.