Recent Advances on Early-Stage Fire-Warning Systems: Mechanism, Performance, and Perspective

Abstract

Early-stage fire-warning systems (EFWSs) have attracted significant attention owing to their superiority in detecting fire situations occurring in the pre-combustion process. Substantial progress on EFWSs has been achieved recently, and they have presented a considerable possibility for more evacuation time to control constant unintentional fire hazards in our daily life. This review mainly makes a comprehensive summary of the current EFWSs, including the working mechanisms and their performance. According to the different working mechanisms, fire alarms can be classified into graphene oxide-based fire alarms, semiconductor-based fire alarms, thermoelectric-based fire alarms, and fire alarms on other working mechanisms. Finally, the challenge and prospect for EFWSs are briefly provided by comparing the art of state of fire alarms. This work can propose a more comprehensive understanding of EFWSs and a guideline for the cutting-edge development direction of EFWSs for readers.

Shape memory polymer-based thermal-responsive circuit switches

“…Until now, novel smart temperature detectors involved the resistance change type, colour change type, and voltage change type. 1,4,5…”

“…Accumulation and increase of localized temperature are generally undetectable until it blossoms out into over-high environment temperature or large-scale flame. 1 However, the localized overheating phenomenon is an innegligible issue because of its provision of ignition pathways for combustible materials ( e.g. , wood, textiles, and electric appliance).…”

DNA-Modified Graphene Oxide Supported on a Fire-Resistant Hydroxyapatite Paper for Timely and Reliable Fire Warning

“…Among carbon-based nanomaterials, the graphene oxide (GO)-based fire warning sensors are most studied due to their ultrafast transformation from the insulated GO to the conductive reduced GO (rGO) in the flame. − Subsequently, the alarm devices connected with GO sensors could be activated to send out the warning signals in as short as 1–5 s upon exposure to the flame. − However, there are two major challenges of GO sensors: (i) the poor flame retardancy of GO makes it hard to survive in the flame for long, thereby leading to a short period of fire warning , and (ii) the sufficiently high temperature is necessary to remove the abundant oxygen-containing groups on the surface of GO. As such, the response temperature of the pure GO sensor is as high as 200 °C. , …”

Graphene Oxide and Hydroxyapatite Nanowire-Based Asymmetric Nanocomposite Papers with Heat-Induced Color and Resistance Switching for Dual-Mode Early Fire Warning

“…In 2018, several research groups proposed that graphene oxide (GO) is an emerging candidate as a sensitive fire warning sensor. − The fire warning mechanism of GO is based on the resistance change under a high-temperature environment due to the removal of the oxygen-containing groups from the surfaces of GO. Since then, various smart fire warning sensors have been extensively reported beyond GO, − including those based on resistance change, − voltage change, − color change, , and shape change. − In addition, the concept of smart fire warning sensors has been extended to the fields of batteries, − supercapacitors, nanogenerators, , and flexible electronics. − Among a variety of fire warning sensors, GO fire warning sensors have been extensively studied, owing to their ultrafast fire warning, outstanding mechanical properties, and high compatibility with flammable polymers …”