Recorded low-reflection in gradient MXene-decorated melamine microwave shielding foam integrated with piezoresistive sensing and energy absorption properties

High-performance electromagnetic interference (EMI) shielding materials with low reflection are urgently required due to secondary electromagnetic pollution. MXene-based shielding materials often encounter a dilemma of high reflectance due to the high conductivity and permittivity of MXene, Herein, ecoflex-encased gradient MXene-decorated melamine foams (eGMMFs) are proposed to achieve both ultra-low reflection and efficient shielding. By designing a gradual increased gradient MXene conductive network and a reflector of reduced graphene oxide, the eGMMF integrates the impedance matching layer, loss layer, and reflective layer, which contributes to a average shielding efficiency of 78.8 dB and an reflection coefficient (R) of 0.022 in the X-band. A recorded low R value of 3.84 × 10^-5 is obtained at 11.52 GHz, which prevails over previously reported MXene-based shields. Meanwhile, the developed eGMMF shows a remarkable piezoresistive sensing and anti-impacting performance. This work provides a new vision and guidance for editing both shielding and absorbing materials integrated with multifunctionality.