According to researchers at MIT, the constant electrical charge that trees give off naturally could be used to power up sensors placed directly on roots or in canopies. The batteries to be used by future such sensor arrays could be recharged from the tree over time. This discovery could eliminate obsolete and costly unmanned weather stations, usually built in hard-to-reach places, such as remote locations or mountainous areas.
 

A further application could be safeguarding national boarders against hazardous chemicals or nuclear traffic, if sensors can relay back information to control centers in real time. According to Shuguang Zhang, associate director of MIT's Center for Biomedical Engineering (CBE) and leader of the study, the sensors could use each other to transmit data to local transmission arrays that would forward them to satellites. A control center in Boise, Idaho, would be responsible for centralizing the information and elaborating an effective response to any situation.
 

The wireless network is already under development, with the first real-life simulations scheduled to begin in the spring of 2009 on a 10-acre patch of forest provided by the Forest Service. Scientists estimate that 4 sensors per acre should be enough to provide sufficient signal amplification until it reaches the satellite. The chargers for the batteries have already been developed, so all that's left to do is calibrate the sensors to take up the minimum amount of energy once they are powered on. The entire system will use common batteries, available at any store and mounting them will be a fairly simple task that will not require the presence of trained professionals.

 
This type of system is considered to be a breakthrough in the field. Provided it works, it will save millions of dollars spent needlessly on re-supplying automated stations throughout the United States. Commercial applications for the sensor network are also under consideration, tough they are still a long way from possible implementation. Once the first batch of tests are successful, the network is to be installed in critical points along the border, where the hazard of dangerous chemicals being introduced into the country is the largest.