Ultrasensitive hybrid optical skin

TL;DR

This paper introduces a highly sensitive optical skin (O-skin) that uses embedded glass micro/nanofibers to achieve ultrahigh sensitivity, fast response, and EMI-free detection, surpassing traditional electronic skins in various sensing applications.

Contribution

The authors develop a novel optical skin using embedded glass micro/nanofibers, enabling ultrahigh sensitivity and fast response in wearable sensors, overcoming limitations of electronic skin.

Findings

Achieved pressure sensitivity of 1870/kPa

Detected vibrations, pulse, and voice EMI-free

Demonstrated optical data glove and tactile sensor

Abstract

Electronic skin, a class of wearable electronic sensors that mimic the functionalities of human skin, has made remarkable success in applications including health monitoring, human-machine interaction and electronic-biological interfaces. While electronic skin continues to achieve higher sensitivity and faster response, its ultimate performance is fundamentally limited by the nature of low-frequency AC currents in electronic circuitries. Here we demonstrate highly sensitive optical skin (O-skin) in which the primary sensory elements are optically driven. The simple construction of the sensors is achieved by embedding glass micro/nanofibers (MNFs) in thin layers of polydimethylsiloxane (PDMS). Enabled by the highly sensitive power-leakage response of the guided modes from the MNF upon external stimuli, our optical sensors show ultrahigh sensitivity (1870/kPa), low detection limit (7 mPa) and fast response (10 microseconds) for pressure sensing, significantly exceeding the performance metrics of state-of-the-art electronic skins. Electromagnetic interference (EMI)-free detection of high-frequency vibrations, wrist pulse and human voice are realized. Moreover, a five-sensor optical data glove and a 2x2-MNF tactile sensor are demonstrated. Our results pave the way toward wearable optical devices ranging from ultrasensitive flexible sensors to optical skins.