It might be easy to replace dead batteries in one’s home clock or smoke detector. But it’s problematic in more complex environments, say, forests, large buildings or airplanes. Here, you need networks with hundreds of battery-powered devices to detect flames quickly and accurately.
Matteo Rinaldi an associate professor of electrical and computer engineering and a researcher from at the Northeastern University, has come up with a solution: a smart detector that wakes itself up from ultra-battery-saver mode using the very flames it is engineered to detect. According to Rinaldi, most flame detectors use their battery on functions like monitoring and processing information. In places such as construction sites or spacecraft, where fires are relatively rare and smoke detection is unrealistic because of the environment, frequent battery replacement tends to be expensive and impractical. Relying on hard wiring can also result in malfunctions. Standby power consumption limits the battery lifetime of the commercially available sensor technology and he is helping eliminate that.
The detector by Rinaldi can nap without using its battery for up to 10 years or until a flame wakes it up. It monitors its environment continuously while in sleep mode. This means the battery is used only in the short intervals in which the device detects a flame and sends a wireless warning signal. It’s a switched off, but alert, wireless system that could protect large and complex areas, such as commercial buildings, construction sites, airplanes, space stations, and forests.
It has two micro contacts separated by a tiny gap. Closing it requires the specific infrared energy from a flame, which heats up one of the contacts, and pushes it down like a microscale diving board to complete the circuit. At that point, energy starts flowing from the battery and the communication device sends the alert. But as soon as a flame’s energy is gone, the circuit opens, and the sensor goes back to sleep.
The sensor relies on a micro-mechanism which is a miniature version of the light switches we use every day. Infrared energy from flames acts like fingers pushing a micromechanical relay to trigger a fire alarm. It happens at micro and nanoscales, the atomic and molecular level.
The team plans to commercialise their zero-power, wireless flame detectors for settings like construction sites, warehouses and forests through a startup company, named Zepsor Technologies.
Shahjadi Jemim Rahman