Highly customizable, ultrawide-temperature free-form flexible sensing electronic systems based on medium-entropy alloy paintings.

High-performance flexible sensing electronics on complex surfaces operating across broad temperatures are critical for aerospace and industrial applications. However, existing flexible sensors and materials face limitations in sensitivity and thermal stability. Here, we report an ink-engineering strategy to directly print single-face MoWNb medium entropy alloy paints on arbitrary surfaces without complicated post-processing. These sensors exhibit exceptional strain sensitivity (gauge factor up to -752.7 at 300 °C), a low detection limit (0.57 με), and superior thermal stability from -150 to 1100 °C. Through a cyclic dispersing/re-printing process, the fully recyclable sensors retain electrical properties and sensing performance. Furthermore, by integrating with a long-range radio module, we demonstrate a wireless sensing system for in-situ and real-time monitoring of a morphing aircraft under various extreme environments. Our findings provide a convenient and efficient approach for the direct fabrication of flexible sensors and the seamless integration into sensing systems that work reliably in harsh environmental conditions.