“As far as we know, this is the first peer-reviewed paper of someone powering something entirely by sticking electrodes into a tree,” said UW professor of electrical engineering Babak Parviz.

He and colleagues will publish their findings in the journal Transactions on Nanotechnology.

Hooking nails to trees and connecting a voltmeter, researcher Carlton Himes found that bigleaf maples, common on the UW campus, generate a steady voltage of up to a few hundred millivolts.

By putting that voltage into a “boost converter,” the UW team was able to produce an output of 1.1 volts.

That’s enough to operate low-power sensors to monitor environmental conditions such as forest fires.

Members of a team from the Massachusetts Institute of Technology who first discovered plant voltage last year have formed a new company to develop forest sensors to exploit the newly discovered power source.

A tree's health may also be determined by measuring its natural voltage.

Photos: University of Washington