Optical skin—
Ultrasensitive skin-like wearable optical sensors based on glass micro/nanofibers


Skin is a magical organ that senses small changes in external stress, temperature, and other environmental factors through a complex network of neural and tactile receptors, and transmits the information to the brain, enabling us to navigate in the changing environment safely and efficiently. Artificial skin sensors are a hot research field in the scientific community today, and their research results are crucial for the development of wearable devices, robots, human-machine interaction, and smart medical devices. Although the research on artificial skin sensors (electronic skin) based on electrical principles has achieved great success, electronic skin faces great challenges in terms of electromagnetic interference, signal crosstalk and large-area integration.

Micro/nano fiber (MNF) is a kind of optical fiber that is dozens of times thinner than human hair. Due to its tight optical confinement, strong evanescent fields, excellent mechanical properties, and small bending radius, MNF offers outstanding advantages in highly sensitive optical sensing. Recently, Professor Lei Zhang and Professor Limin Tong in Nanophotonics Research Group at the College of Optical Science and Engineering of Zhejiang University reported a highly sensitive skin-like wearable optical sensor based on MNF. The flexible polymer film-embedded MNF likes a nerve in the skin. When the MNF is subjected to external stimuli such as pressure, vibration, and bending, the optical signal output from the MNF changes accordingly. High-sensitivity sensing of weak pressure (0.1 Pa), high-frequency vibration (20 kHz), angle, sound and pulse is achieved by detecting light signals in real time. This "optical skin" sensor can not only be attached to human skin to monitor physiological indicators, but also integrate with gloves to sense the movement of the hand joints, enabling remote and precise manipulation of a mechanical hand. This research has opened up new avenues for the development of new tactile sensing systems and smart robots in the future.

Figure 1 (a) Photograph of a bent MNF-embedded PDMS patch. (b) photograph of light leaking out of a SLWOS upon a finger touch.


About The Group

The Nanophotonics Research Group is in the College of Optical Science and Engineering, and the State Key Laboratory of Modern Optical Instrumentation at Zhejiang University. This group explores the science, technology and art of light on the nanoscale. Their research interests include theoretical design, experimental preparation, micro-nano manipulation, photoelectric characterization, functionalization and other cutting-edge foundations and application techniques for low-dimensional photonic structures and devices. This group has 4 professors and 3 associate professors, and they have published more than 200 papers in peer reviewed journals such as Nature, Nature Communications, Advanced Materials, Nano Letters, and so on. They have obtained dozens of Chinese patents and won the first prize of Zhejiang Natural Science. Also, they have presided over several research programs such as the National Key Research and Development Project of China and the National Natural Science Foundation of China.


Zhang L, Pan J, Zhang Z, Wu H, Yao N et al. Ultrasensitive skin-like wearable optical sensors based on glass micro/nanofibers. Opto-Electron Adv 3, 190022 (2020).