Carbon Fiber/Methyltrimethoxysilane/Graphene Composite Aerogel for High-Strength Strain Sensors

Because of their special physical characteristics, graphene aerogels have been produced for sensing applications; nevertheless, their lack of mechanical features prevents them from being used further. In this study, a hydrophobic carbon-fiber and methyltrimethoxysilane-reinforced graphene composite aerogel (aCF-MGA) with a three-dimensional interconnected hierarchical microstructure was designed and developed by a freeze-drying process with a distinct honeycomb structure. Methyltrimethoxysilane (MTMS) and graphene oxide (GO) create a dense interlayer porous network and solid-layered structure through covalent cross-linking and hydrogen bonding. Because alkali-treated carbon fiber (aCF) offers strong mechanical support, aCF-MGA aerogel has exceptional mechanical qualities and a distinctive “porous honeycomb” structure. The aCF-MGA aerogel-based sensor is capable of detecting a wide range of motion signals in compression, because of the synergistic effect of multiple substances. It has a high sensitivity of 27.34 kPa^–1 and excellent properties like ultrahigh elasticity, ultralight density (4.5 mg/cm³), highly conductive (2.85 S/cm), high fatigue compression resistance (10,000 cycles), extremely short response time (96 ms), and short relaxation time (68 ms). This enables them to detect a variety of motion signals and implies that the aCF-MGA aerogel may find use in human–machine interaction and sports health monitoring as a possible material for wearable protection devices and piezoresistive sensors.