Flexible, multimodal, electrical-sensing-optical-transmission μfiber-sensors via an on-fiber printed electronics strategy.

Optical fiber sensing offers inherent advantages in long-distance and interference-free transmission. However, it faces a major challenge in achieving self-decoupling and multimodal detection. Here, inspired by the firefly's bioluminescent mechanism, we propose a flexible, distributed, multimodal electrical-sensing-optical-transmission fiber sensor (ESOT FiSensor) that can convert diverse electrical sensing signals into optical signals through on-fiber hybrid circuits. The ESOT FiSensor realizes distributed and simultaneous monitoring of four physical parameters, including vibration, pressure, temperature, and strain, through only a single optical fiber, and it can maintain long-distance transmission and strong electromagnetic interference immunity within 0-1000 Hz, far superior to purely electrical sensors. The on-fiber electro-optical circuits were fabricated by combining conformal additive printing and flexible hybrid electronics integration, and the printing technique achieves a resolution of 260 nm directly on submillimeter fibers as fine as human hair (∼60 μm). The performance of the ESOT FiSensor has been validated in three representative scenarios: multimodal sensing under complex environmental conditions, distributed sensing on aircraft skins, and wearable sensing for human-machine interaction. The ESOT FiSensor establishes a powerful and scalable platform for long-distance, multimodal signal perception in complex and dynamic environments. It provides a pathway toward transforming optical fibers from passive communication media into active multimodal distributed sensing networks in the near future.