A “fire alarm wallpaper” designed by researchers can now be used to spot a fire, send of an alarm, and also thwart it from spreading. It is made from eco-friendly and noninflammable materials. Some such materials can be found in teeth, bone, and hormones.
This is how the wallpaper works – on exposure to heat, it changes into an electrically conducive material from an electronically insulating one, resulting in an automatic triggering of the alarm which comprises of loud sounds and warning lights.
How Does the Material Work
Coming back to the composition of the wallpaper, it is formulated from hydroxyapatite. It is the main inorganic component found in teeth and bone. And even though hydroxyapatite is essentially inflexible and brittle, making ultralong nanowires from hydroxyapatite makes it highly flexible, thereby making it perfect for making wallpaper.
The team of researchers added an ink-based thermosensitive sensor on to the wallpaper to make into a smart material so that it can automatically sound an alarm in response to the fire. The thermosensitive sensor is embedded on the wallpaper surface leveraging an uncomplicated process called drop-casting with an ink that contains graphene oxide. The extremely small sensor is fitted on the back of the fire- resistant wallpaper makes it inconspicuous. It is protected by the wallpaper which is fireproof.
Graphene oxide, which at normal room temperature is electrically insulating, is what has been used to make the sensor. But on exposure to heat, the groups having oxygen are removed, hence making the material conductive.