A high-performance photonic-ionic E-skin with synergistic electronic/optical sensing for motion tracking

The integration of visualization and electrical feedback in biomimetic electronic skin (E-skin) for real-time motion tracking has attracted significant attention in wearable electronics. To facilitate human-readable interactive feedback and improve the overall performance of E-skin, particularly regarding mechanical compliance, sensitivity, and stability, we propose a novel high-performance photonic-ionic skin (PI-skin) based on mechanochromic photonic ionogel. The PI-skin, prepared by incorporating aligned magnetic colloids into an ionogel matrix, integrates interactive structural coloration and electrical responses to external stimuli, achieving dual-mode precise motion recognition. Due to the enhanced hydrogen bonding and electrostatic interactions within the ionogel matrix, the PI-skin exhibits excellent mechanical properties (tensile strain >1000%), remarkable adhesive strength (peeling force >7 kPa), high sensitivity (gauge factor = 1.42 at straining 0%–300% and 2.71 at straining 300%–500%), rapid response time (120 ms), and exceptional mechanical compliance (>500 continuous cycles). More importantly, such PI-skin demonstrates ultrafast and highly accurate optical/electrical dual-signal motion detection, thereby facilitating posture correction during sitting and encoding of vocal cord vibrations during speech. We anticipate that this versatile PI-skin will possess substantial potential in the field of wearable electronics, and may inspire the design of next-generation E-skin for human-computer interaction and personalized healthcare applications. © 2025 Elsevier B.V.