Ultrasensitive and superelastic high-performance aerogel based on hollow carbon nanofiber/graphite composite with piezoresistive sensing applications

The compressible multifunctional carbon aerogel is critical to the development of smart electronics, but it encounters considerable hurdles. Building pliable and completely conductive aerogels for piezoresistive pressure sensors is frequently impeded by the balancing act between elastic response and electric conductivity. This research presents the fabrication of conductive carbon aerogels that exhibit high flexibility and compressibility using a facile method of compositing hollow carbon nanofibers (HCNF) prepared via electrostatic spinning and freeze-drying. The combination of graphite and HCNF shows an ordered, interconnected porous structure consisting of a "layer pillar" skeleton with connected fibers. Due to its stable porous structure, the carbon aerogel has an ultra-low density (18.07 mg/cm3) with a compressive strain of up to 99 %. Under cyclic compression, this carbon aerogel exhibits excellent compressive resistance, stable linear piezoresistive response, ultra-high sensitivity (3.42 kPa−1), good reproducibility after 200 cycles, and ultra-fast response time (240 ms). These properties make it an ideal candidate for high-performance wearable pressure sensors for monitoring human motion. Thus, this work provides a highly flexible, lightweight, and robust multifunctional aerogel sensor that holds great promise for smart wearable sensing, medical devices, and smart robotics.