Researchers from China’s Shanghai Institute of Ceramics have developed a novel fire alarm wallpaper that detects and prevents fire from spreading in a household.
According to the researchers, the wallpaper transforms itself from an electrically insulating state into an electrically conductive one, causing it to automatically trigger an alarm that generates loud sounds and warning lights.
“Compared with flammable commercial wallpaper, the fire-resistant wallpaper is superior owing to its excellent nonflammability, high-temperature resistance, and automatic fire alarm function,” Professor Ying-Jie Zhu told Phys.org.
“The fire-resistant wallpaper has a white color, mechanical robustness, and high flexibility, it can be processed into various shapes, dyed with different colors, and printed with a commercial printer. Therefore, the fire alarm fire-resistant wallpaper has promising applications in high-safety interior decoration to save human lives and reduce the loss of property in a fire disaster.”
The new wallpaper is composed of environment-friendly hydroxyapatite, which is the primary inorganic component of bone and teeth.
Although hydroxyapatite is typically brittle and inflexible, the researchers found that forming ultralong nanowires made of hydroxyapatite gives the material a high flexibility suitable for making wallpaper.
The nonflammable wallpaper was transformed into a ‘smart material’ by incorporating an ink-based thermosensitive sensor onto the wallpaper, making it capable of automatically sounding an alarm in the event of a fire.
The thermosensitive sensor is fabricated on the surface of the wallpaper by a simple drop-casting process using an ink containing graphene oxide. The tiny sensor is placed on the backside of the fire- resistant wallpaper so that it is out of sight and protected by the fireproof wallpaper.
According to the researchers, the sensor is composed of a modified graphene oxide, which makes it electrically insulating at room temperature. However, when exposed to heat, the oxygen-containing groups are removed, making the material highly conductive.
Image and content: Shanghai Institute of Ceramics