LEGO Inspired Assemble Strategy for Fabricating BN-CNT-BN Multilayer Kevlar Based Composites as High-Performance Temperature Sensor and Fire Alarm

Abstract

A new generation of artificial intelligence devices is developing toward miniaturization and higher working power, which result in a higher heat flux density and present a potential fire hazard. Current fire alarm sensors normally adopt electrically conductive materials and not compatible with surface insulation function to work under short circuit triggered fire disaster. Here, we propose a novel concept and fabrication methods to manufacture durable and fast response fire alarm with surface electrically insulative. We initially separate the sensing and fire proof function of fire alarm by creating multilayer structure, where the conductive, thermally sensitive layer is sandwiched by two fireproof layers. The sensor is fabricated by the unique LEGO-inspired assemble strategy by creating nanobridge to coat fire proof layer on the thermal sensitive layer. The sensor exhibits an ultrafast response and recovery time with only 113.54 ms and 111.96 ms, along with great stability and durability under several cycles. Also, the surface BN-ANF layer provide protection for the internal thermal sensitive layer, which insulate the oxygen and suppress the decomposition of carbon nanotubes, which enable the sensors to be applied to fire alarm properties. Under fire attack, the sensor exhibits a fast response speed of 3s and a long duration over 1200s. And the fire proof mechanism is also applied to improve the fire safety of joule heating film under simulated short-circuit conditions. This new design concept and fabrication strategy improve the fire safety of the composite film and offer new inspiration for high-performance flexible sensors.