Researchers have come up with what they call a "fire alarm wallpaper" which can not only detect a house fire, but also sound an alarm and even help to restrict the spread of fire. The wallpaper is made from hydroxyapatite, an inorganic material which occurs in bone and teeth, and which is resistant to fire. However, the wallpaper's real smarts are down to an ink-based on graphene oxide.

Graphene oxide is a thermosensitive material in that it's an electrical insulator at normal temperatures but conducts electricity when heated. This means it can be used to trigger an alarm in the presence of heat, making it potentially useful in the detection of fires. It comes with certain challenges, though.

For one, the sensors initially lasted only 3 seconds, though by modifying them with polydopamine, the team upped this to more than 5 minutes. This would still need to be increased significantly for real world use, unless used alongside conventional fire detection.

The researchers say the sensors respond to the heat from fire in about 2 seconds, and can be protected from direct fire damage by being placed on the back of the wallpaper.

Leader researcher Professor Ying-Jie Zhu is forthright in talking up the technology. "Compared with flammable commercial wallpaper, the fire-resistant wallpaper is superior owing to its excellent nonflammability, high-temperature resistance, and automatic fire alarm function," 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 research even suggests that widespread adoption of the wallpaper could reduce loss of property.

Though hydroxyapatite is usually brittle, the team has already established that it can be formed into long thin threads, making it suitable for wallpaper production. The researchers are hopeful that the technology can be adapted for other uses. "We have also been exploring various applications of the new kind of fire-resistant paper based on ultralong hydroxyapatite nanowires in many other fields, such as preserving important paper documents, energy, air purification, water treatment, environment protection, anti-counterfeiting, flexible electronics, and biomedical uses," says Zhu.

Graphene oxide will be familiar to long-time New Atlas readers, whether from potential use in dental fillings, water purification, or moisture-controlled robots. Polydopamine is derived from the neurotransmitter dopamine and has been the subject of a variety of nanomaterials research in recent years. Hydroxyapatite, meanwhile, has been touted for potential use in stretchable bone implants.

The research was carried out at the Shanghai Institute of Ceramics at the Chinese Academy of Sciences. The team's paper was published recently in the journal ACS Nano.

You can see a video of the prototype in action at the source link below.

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