Advanced functional composites have attracted a great attention for fabricating flexible devices. In this article, the GnP/epoxy composite film was prepared by mixing graphene platelets (GnPs) with epoxy through sonication process. The morphology, mechanical properties, and electrical conductivity of the prepared composites were investigated. As the GnP contents increased from 2.5 to 7.5 vol%, the composites showed an increase in strain sensitivity with the rapid decrease in the strain gauge to 4.4. Additionally, when dynamic movement of the flexible film was performed, at bending and twist angle of 135° and 180°, respectively, steady increase in both resistance changes were detected and compared. The electrical resistance of the flexible was measured over a temperature range of 20–95°C, an increase in temperature lead to a linearly equivalent increase in resistance. The composites can also detect slight pressure changes at 2 kPa compression force with rapid decrease of resistance. Additionally, fatigue test was performed with stable, sensitive, and no distinguishable reading under 2,000 stretching cycles. The composite film exhibits an excellent self‐sensing responds when fracture occurred. Thus, the obtained highly flexible, conductive, and mechanical robust composite sensor can be applied as advanced composites sensors for health monitoring.

Detecting and locating accurately structure damages at an early stage is essential to minimization of catastrophic disasters, prevention of fatalities and provision of cost‐effective maintenance. We herein report a facile approach to detect structure damages and to accurately identify their locations by using an electrically conductive epoxy/graphene nanocomposite film. A percolation threshold of electrical conductivity was observed at 0.58 vol% of graphene platelets (GnPs, ~3 nm in thickness and ~15 μm in length); electrical conductivity of 3.3 S/cm was obtained at 9.00 vol% of GnPs. The epoxy/GnP composite film containing 9.00 vol% of GnPs was employed as an array of electrically conductive paths in horizontal and vertical directions to detect and locate structure's damages. Thermal stability and temperature coefficient of the composite film were studied. Relative resistance change due to temperature effect was fitted into an exponential function, which showed strong correlation with the temperature change. This implies that an algorithm can be developed to compensate drift errors in resistance measurement due to temperature variation. With the help of Internet of Things, our self‐sensing epoxy/graphene nanocomposite films have great potential for smart aerospace structural health monitoring.