Scientists at Huazhong University of Science and Technology in China have created a groundbreaking fiber sensor inspired by the way fireflies produce light. The new device, called the ESOT FiSensor, turns ordinary optical fibers into active, multimodal sensing networks. It can simultaneously monitor vibration, pressure, temperature, and strain through a single fiber while transmitting signals over long distances with complete immunity to electromagnetic interference.
Optical fibers already form the backbone of global communications, carrying data across hundreds of millions of kilometers. Many researchers have tried to use them for sensing as well. However, conventional optical fiber sensors usually can detect only one or two physical quantities at a time and often require complex equipment. Electrical sensors, on the other hand, suffer from signal loss and interference when signals travel long distances or pass through environments filled with electromagnetic noise.
The new ESOT FiSensor solves these problems by combining the best of both worlds. It takes electrical signals from multiple sensors and converts them directly into light signals right on the surface of the fiber. The light then travels through the fiber core without losing quality or being affected by interference.
The key innovation lies in an on-fiber hybrid electronic circuit. Using a high-precision printing technique called electrohydrodynamic printing, the researchers can create tiny conductive circuits directly on the curved surface of polymer optical fibers — even fibers as thin as a human hair. This printing method achieves a record resolution of 260 nanometers on such tiny fibers. Tiny light-emitting diode chips (μLEDs) are then mounted on the fiber. When external sensors detect vibration, pressure, temperature, or strain, the circuit converts those signals into voltage that lights up the μLEDs. Each μLED emits light of a different color (wavelength). These colored light pulses travel together through the same fiber and are decoded at the receiving end by a spectrometer.
Tests show the system works exceptionally well. After traveling through 50 meters of optical fiber, the ESOT FiSensor still retains more than 90 percent of its original sensitivity. In contrast, traditional electrical sensors lose about 20 percent of their performance over the same distance. When exposed to strong electromagnetic interference at 20 Hz, conventional electrical sensors become unstable and distorted, while the ESOT FiSensor continues to transmit clear, accurate signals.
The researchers demonstrated the technology in three realistic scenarios. First, they mounted vibration and temperature sensors on a model car. The ESOT FiSensor successfully tracked both signals at the same time while the car was moving and passing near a heat source. Second, they placed a small array of temperature sensors on the surface of an aircraft wing model. The system accurately mapped temperature changes across different positions along the wing through a 50-meter fiber, showing its potential for aerospace structural health monitoring. Third, they created a wearable version using strain sensors. The device recognized ten different hand gestures with 98.15 percent accuracy and successfully controlled a robotic hand in real time.
Beyond its immediate performance, the ESOT FiSensor offers a scalable new platform. Because the circuits are printed directly onto the fiber, the technology is flexible, lightweight, and easy to integrate into existing optical fiber networks. The researchers believe it could transform billions of kilometers of installed optical fiber from passive communication channels into active, distributed sensing systems for smart cities, unmanned vehicles, subsea monitoring, and harsh industrial environments.
The study, titled “Flexible, multimodal, electrical-sensing–optical-transmission μfiber-sensors via an on-fiber printed electronics strategy,” appears in the journal National Science Review (DOI: 10.1093/nsr/nwag250).
Huazhong University of Science and Technology is a leading research university in Wuhan, China, renowned for its strengths in advanced manufacturing, flexible electronics, and optical engineering. The work was carried out at the university’s State Key Laboratory of Intelligent Manufacturing Equipment and Technology and Flexible Electronics Research Center.
National Science Review
Experimental study