If forest sensors existed, they could warn of forest fires and especially dry, dangerous conditions. But forests are typically short on electronic gadgetry and sockets for plugging in such electronic warning devices.

So an invention coming out of MIT is most welcome.

While it's common knowledge among scientists that trees produce extremely small amounts of electricity, no one thought of a use for this "natural electricity" until now.

MIT researchers have devised a sensor system to send forest fire warnings, tapping into the tree's own natural power supply for the juice.

Each tree selected to become a neighborhood sentry will be fitted with a contraption that plugs into its electricity supply. Each sensor in the MIT system will be equipped with a battery.

The battery will be very slowly recharged using electricity naturally generated over a very long period by the tree itself, "just like a dripping faucet can fill a bucket over time," said Shuguang Zhang, one of the researchers on the project and the associate director of MIT's Center for Biomedical Engineering.

Four times a day, or on demand during emergencies such as forest fires, signals will be transmitted wirelessly to let the U.S. Forest Service know the temperature and humidity readouts of trees deep in forests. Each signal will hop from one sensor to another, until it reaches an existing weather station that beams the data by satellite to a forestry command center in Boise, Idaho.

Remote, automated weather stations are already included in the tools the Forest Service uses to predict and track fires. But they are expensive to operate and therefore sparsely distributed. Manually recharging or replacing batteries at hard-to-reach locations makes it impractical and too costly to monitor some areas as well as they should be.

Additional sensors would provide more detailed local climate data. When trees become tinder-dry they start loosening their grip in the soil. This subtle movement would also be registered along with humidity and temperature readouts.

Next spring, the first field testing of the wireless sensor network, which is being developed by MIT spinoff VoltreePower, will begin on a 10-acre plot of land provided by the Forest Service.

Via MIT