The Study of Bioelectricity on the Trees and Their Applications as Power Sources

The paper is intrigued by an Internet circulated report about running electrical circuit entirely off power in trees by the researchers in University of Washington [1]. Today, it is highly desirable to find green, effective and renewable energy resources globally. It is very interested to know that how much the electric potential difference (EPD) on the tree is, and how and where it can be used. The paper is set up for the above questions. Firstly, three kinds of trees, a broad-leaved tree, a coniferous tree and a ginkgo, are chosen to record the bioelectric current and voltage differences every day for one year from December 2010 until November 2011, and the environment humility and temperature are also recorded at same time. From the recorded data, we obtain that: there do exist the voltage difference and bioelectric current in the trees, and the values change with the tree species, monitoring site, environment temperature and humidity. Ginkgo (including root, and trunk) has 600 ~ 800 mV voltage differences and 5 ~ 30 uA current. A broad-leaved tree has 500 ~ 750 mV voltage differences and 6 ~ 40 uA current. Coniferous tree has 350 ~ 700 mV voltage differences and 3 ~ 20 uA current, which has the smallest electric potential differences among the three kinds of trees. The synthetical analysis results indicate that the broad-leaved tree may be the most suitable tree species for the power source. Secondly, based on the measured bioelectricity data of the trees, the paper explored the technical proposal to harvesting the energy from trees. LTC3588-1 chip of LINEAR TECHNOLOGY in United States is chosen as the energy harvester and a preliminary energy harvesting solution from trees energy sources to power a Microprocessor with a Wireless Transmitter is proposed. Finally, the applications of tree power sources are discussed by three levels. The paper gives a beautiful image with the tree power sources in the near future, wherever you are walking in the street, park, cam- or even at wild, only there is a tree, you can open your computer at any time, plug the line into the tree, and begin your work or communication with the outside as long as you like. The trees will provide you endless power.