Twisted Optical Micro/Nanofibers Enabled Detection of Subtle Temperature Variation

Abstract

The detection of subtle temperature variation plays an important role in many applications, including proximity sensing in robotics, temperature measurements in microfluidics, and tumor monitoring in healthcare. Herein, a flexible miniaturized optical temperature sensor is fabricated by embedding twisted micro/ nanofibers in a thin layer of polydimethylsiloxane. Enabled by the dramatic change of the coupling ratio under subtle temperature variation, the sensor exhibits an ultrahigh sensitivity (−30 nm/°C) and high resolution (0.0012 °C). As a proof-of-concept demonstration, a robotic arm equipped with our sensor can avoid undesired collisions by detecting the subtle temperature variation caused by the existence of a human. Moreover, benefiting from the miniaturized and engineerable sensing structure, real-time measurement of subtle temperature variation in microfluidic chips is realized. These initial results pave the way toward a category of optical sensing devices ranging from robotic skin to human−machine interfaces and implantable healthcare sensors.

A Review of Wearable Optical Fiber Sensors for Rehabilitation Monitoring

“…For instance, during hand trauma or post-surgical rehabilitation, monitoring finger temperature can help to identify circulatory disorders and prevent complications in a timely manner. Utilizing optical fiber sensors for temperature monitoring enables continuous, real-time tracking of finger temperatures and offers scientific data to support rehabilitation treatments [ 93 , 94 ].…”

3D-Printed Soft Temperature Sensors Based on Thermoelectric Effects for Fast Mapping of Localized Temperature Distributions

“…The growing demand for the stable operation of electronic devices under external deformation has significantly advanced research into soft electronics. , These have been explored in various configurations for use in diverse environments and conditions, particularly for applications in human–machine interface sensing, motion tracking, and electronic skin. The critical role of temperature sensors in these applications is emphasized for real-time detection of target temperature changes, preventing thermal breakdowns or overheating to ensure device stability. − These sensors must rapidly detect localized, subtle temperature variations across a broad range, adhering perfectly to any surface shape to accurately monitor temperature changes and protect both industrial machines and skin-interfaced wearable modules from overheating, even under extreme conditions involving mechanical deformation. − Consequently, the development of temperature sensors that establish conformal interfaces with complex or changing shapes is crucial, demanding high sensitivity, lightweight, flexibility, and high cyclic stability to meet these challenges.…”