A new alarm system powered by the movement of trees in the wind could help detect and fight forest fires. Quick response to forest fires can significantly reduce the damage and loss of property and life.
In a new study, a team of Michigan State University scientists designed and fabricated a remote forest fire detection and alarm system powered by nothing but the movement of the trees in the wind.
Known as MC-TENG — short for multilayered cylindrical triboelectric nanogenerator (TENG) – the device generates electrical power by harvesting energy from the sporadic movement of the tree branches from which it hangs, explains a statement.
“As far as we know, this is the first demonstration of such a novel MC-TENG as a forest fire detection system,” said lead author Changyong Cao in the statement. “The self-powered sensing system could continuously monitor the fire and environmental conditions without requiring maintenance after deployment.”
Cao believes that early and quick response to forest fires will make the task of extinguishing them easier, significantly reducing the damage and loss of property and life.
Traditional forest fire detection methods include satellite monitoring, ground patrols, watch towers, among others, which have high labor and financial costs in return for low efficiency.
Current remote sensor technologies are becoming more common, but primarily rely on battery technology for power.
TENG technology converts external mechanical energy – such as the movement of a tree branch – into electricity by way of the triboelectric effect, a phenomenon where certain materials become electrically charged after they separate from a second material with which they were previously in contact, according to the statement.
The simplest version of the TENG device consists of two cylindrical sleeves of unique material that fit within one another. The core sleeve is anchored from above while the bottom sleeve is free to slide up and down and move side to side, constrained only by an elastic connective band or spring.
As the two sleeves move out of sync, the intermittent loss of contact generates electricity. The MC-TENG are equipped with several hierarchical triboelectric layers, increasing the electrical output.
The MC-TENG stores its sporadically generated electrical current in a carbon-nanotube-based micro supercapacitor. The researchers selected this technology for its rapid charge and discharge times, allowing the device to adequately charge with only short but sustained gusts of wind.
Photo courtesy of Michigan State University