flexible deformation methods, excellent stability, and easy assembly. [17][18][19] Generally, piezoresistive sensors work on the principle of regulating the internal structure of conductive materials to cause a change in resistance. [20] Therefore, constructing suitable conductive materials is crucial in developing high-performance piezoresistive sensors.Recently, 3D aerogel-based conductive materials have been regarded as ideal candidates for piezoresistive sensors due to their high porosity, good elasticity, and low density. [21] The selection of sensing materials in conductive aerogels is generally focused on nanoparticles, conductive polymers, and carbon materials. [22][23][24] Among them, graphene-based aerogel plays a vital role in piezoresistive sensors due to its unique physical and chemical properties. [25] However, the poor conductivity of graphene aerogel always causes low sensitivity in the piezoresistive sensor, which significantly limits its practical application in the sensing field.MXene is a graphene-like 2D material composed of transition metal carbides/nitrides or carbides. [26] The general chemical formula of MXene is M n+1 X n T x , where M is a transition metal, X is C or N, and T x represents a functional group. The good electrical conductivity of MXene enables it to be a potential alternative for piezoresistive sensor sensing materials. [27] Unfortunately, similar to other 2D materials, MXene is easy to stack, which may reduce the service life of the piezoresistive devices. Besides, the low aspect ratio and weak gelling ability of MXene nanosheets make it difficult to form a continuous porous structure. [28] Though intense efforts have been made to apply MXene to piezoresistive sensors, [29] it is still a big challenge to prepare MXene-based aerogels as piezoresistive sensors with high sensing performance, fast response time, and excellent fatigue resistance.Herein, we report our success in realizing a highperformance piezoresistive device based on nanofiberreinforced MXene-reduced graphene oxide (rGO) aerogel (named alkaline-treated polyacrylonitrile nanofibers (aPANFs)/ MX-rGA). The aPANFs/MX-rGA has a 3D interconnected porous structure, in which alkaline-treated polyacrylonitrile 3D aerogel-based piezoresistive sensors have attracted tremendous attention due to their high sensitivity and excellent mechanical properties. Here, a novel piezoresistive sensor with ultrahigh linear sensitivity is tactfully designed and prepared based on nanofiber-reinforced MXene-reduced graphene oxide aerogel. The presence of MXene endows the piezoresistive sensor with high conductivity. Besides, the nanofibers can act as a scaffold to improve the compression resilience of the aerogel significantly by penetrating the entire aerogel network. Furthermore, due to the synergy effect among the multiple components, the prepared piezoresistive sensor exhibits outstanding performance, including high linear sensitivity (331 kPa −1 from 0 to 500 Pa, 126 kPa −1 from 500 Pa to 7.5 kPa), fast response time (load 71 ms, ...
