Trees power this alarm system for remote forest fires
Scientists in Michigan have developed a forest fire alarm system. It not only can detect when a blaze begins but also call for help. This battery-free device dangles like an ornament from a tree and harvests all the energy it needs from the natural swaying of branches. Such a sensor could watch the woods for a decade without human attention.
“It’s a great idea,” says engineer Chris Knight in Newcastle, Australia. He works at CSIRO, Australia’s national research agency. He didn’t contribute to the new work but he knows about wildfire sensors. A few years ago he also developed an idea for a tree-powered one. Such systems need only a trickle of power to smell smoke or detect rising heat, he says.
Changyong Cao agrees. “For forest-fire monitoring, you don’t need high amounts of energy,” notes this engineer at Michigan State University, in East Lansing. Cao led the team behind the new device. It recharges itself about every 10 minutes with just enough power to take a measurement. That’s plenty of time, he says, “to generate sufficient energy.”
If it detects a fire, the sensor signals a device up to a mile away. That hub can relay an alarm. It can collect such data from tens or even hundreds of sensors, Cao says.