Detecting fires with the Internet of Things

An integrated fire-detecting technology

Worldwide, house fires are a major cause of mortality. In the United States, they are responsible for nearly 4000 deaths each year; in Europe, the annual house fire fatality estimate is around 5000 deaths.

People regularly list “house fire” as a top home safety concern, but they don’t always take the necessary steps to protect themselves. In the United States, for example, only around half of homes have smoke detectors, even though they are legally mandated.

Similarly, the European Fire Safety Alliance reports that in nine European countries, smoke detectors are not installed in more than half of homes where fatal house fires occur. The presence of built-in early warning systems could help save lives in homes that lack smoke detectors or have detectors that are improperly installed.

The team at Shenzhen University has developed a fire-warning technology that could be integrated into children’s clothing. The technology is designed to alert parents when a fire breaks out near a child who is sleeping or otherwise unattended, while playing alone in a bedroom, for example.

The sensing system uses carbon nanotubes — tiny, hollow tubes made of carbon atoms — to convert both the light and heat produced by fire into electricity. When the sensor detects a fire, it triggers a warning message that is delivered to a parent’s cell phone.

Guangming Chen, a distinguished professor at Shenzhen University and one of the researchers who worked on the project, said the sensor’s ability to detect both light and heat results in an enhanced signal and faster response time compared to a heat sensor alone. Those extra seconds, Chen said in an email, can provide enough time for parents to “take quick action to ensure their child’s safety, and prevent the fire from further spreading”.

Though the paper focused on children’s clothing, Chen said the sensors could also be used to send a house fire alert to someone who is sleeping or isn’t at home. “With a proper setup, the online computer can further transmit the ‘house on fire’ message to the user’s cell phone,” he said. “In addition, when the response is triggered, a relay on the unit can be connected to an alarm or similar device to alert neighbors or people around that the house is on fire so that they can assist the homeowner with a timely response.”

The accuracy of the alarm in the laboratory was nearly 100%, making it less fallible than a battery-powered smoke detector, he added. Chen also believes the technology could be integrated into home appliances, especially those that generate heat and are often involved in triggering house fires.

“This innovative material can monitor the temperature changes of various devices, including stoves and heaters. Upon detecting a temperature deviance, this technology can help prevent overheating and potential fire hazards,” he said.

Challenges and limitations

Prabal Dutta, an associate professor of electrical engineering and computer sciences at UC Berkeley who was not involved in the study, said the material described in the paper “could find unconventional applications,” but that it might not be practical for use in children’s clothing.

“You would also need to include a variety of electronics in addition to the sensing, which doesn’t seem particularly practical today,” Dutta said in an email.

He also added that it’s hard to know exactly how the technology could be used, since the research isn’t clear about certain details, such as the specific characteristics of the material and what makes it better than other technologies that have similar applications.

“The paper does describe an interesting material that is responsive to heat and light, said Dutta, “and perhaps it opens the door to new kinds of sensors.” But, he notes, it may be a little early to draw conclusions about its true potential.

At this stage, it’s hard to know if the material will work in new applications or if it will simply be used to enhance existing technologies. Real-world applications can have complex limitations and demands, so more research will be needed to uncover the material’s true capabilities and its potential place in the IoT.

Feature image credit: Signature June on Unsplash