Self-Oriented Gradient Ionic Skins for Dual-Function Electromagnetic Shielding and Self-Powered Sensing

Abstract Ionic skins (I-skins) integrated with high-performance electromagnetic interference (EMI) shielding, self-powering functionality, and sensitive pressure detection are critically needed for soft electronics, yet remains a considerable challenge. Herein, we report a facile diffusion-complexation strategy for fabricating self-oriented gradient MXene/polyelectrolyte hydrogels, which function effectively as self-powered I-skins with outstanding EMI shielding and pressure-sensing capabilities. A pivotal feature of our method is the concurrent coupling of two processes: osmotic pressure gradient- induced in-plane self-orientation of MXene nanosheets and diffusion-complexation reaction-induced spontaneous formation of a longitudinal charge gradient. This charge gradient endows the I-skins with a pressure-sensitive self-polarized potential, while the in-plane aligned MXene network imparts both exceptional EMI shielding performance and high-pressure sensitivity. Consequently, the resulting I-skins exhibit a high EMI shielding effectiveness of 48 dB, along with outstanding self-powered sensing capability that delivers a high sensitivity (3.067 mV kPa −1 ), a broad sensing range (0.05–80 kPa), a fast response time (120–130 ms), and a low detection limit for pressure (0.05 kPa). This work offers a new and scalable strategy for integrating high sensitivity, energy autonomy, and superior EMI shielding into advanced I-skins for broader applications.