Superelastic, fatigue resistant and heat insulated carbon nanofiber aerogels for piezoresistive stress sensors

Ultralight flexible carbon aerogels have been applied in many fields but are always hampered due to their weak mechanical stability, large energy dissipation, and complex preparation methods. Here, a novel polyimide-derived carbon nanofiber aerogel with high fatigue resistance and excellent flexibility is prepared by using the designed “fiber gluing” to construct the elastic continuous fibrous network. The as-prepared carbon nanofiber aerogels exhibit ultralow density of 6.6 mg cm⁻³, excellent fire-resistant performance when exposing to alcohol flames (650 °C), and robust elastic resilience even under 55% compressive strain. In particular, the carbon nanofiber aerogels show ultralow plastic deformation (only 1.3%) and low energy dissipation (<0.22) after 1000 cyclic loading-unloading tests at 55% compressive strain. Benefiting from their excellent flexibility and robust mechanical stability, the as-prepared carbon nanofiber aerogel are a promising candidate in the application of wearable devices and piezoresistive stress sensors.