Fabrication\nof Thermochromic Photonic Crystal Stickers\nwith Highly Sensitive Response for Non-open Fire Sensing

Giving\nTimely warnings for fire is very crucial for fire prevention\nand the protection of people’s lives and property. However,\nmost current fire warning sensors give warnings above 200 °C,\nwhich are not conducive to efficient and accurate warnings. Therefore,\nit is important to develop high-temperature sensors that can give\ntimely, portable warnings at low temperatures (100 to 200 °C).\nHerein, simple and portable nonopen flame thermochromic photonic crystal\n(PC) stickers were constructed using ZnS nanoparticles and polyethylene\n(PE) films as the main components. The structural color of the PC\nstickers changed due to the chain motion of PE chain, and the changement\nof the refractive index of the materials when heating. Thus, an early\nfire warning sensor (EFWS) was designed based on the structural color\nchange of PC stickers. The EFWS can give timely and visible sensing\nin 0.8 s at 115 °C. The EFWS based on PC stickers can be combined\nwith indoor surveillance cameras for nonopen fire warnings and key\nplace monitoring (e.g., electrical equipment) in households, aircraft,\nelectrical appliances, substations, etc.