Optical Microfibers for Sensing Proximity and Contact in Human–Machine Interfaces

• DOI: 10.1021/acsami.1c23716
• Publication Date: 2022-03-15T17:46:29Z
• Authors: Haitao Liu; Xingda Song; Xiaoyu Wang; Shuhao Wang; Ni Yao; Xiong Li; Wei Fang; Limin Tong; Lei Zhang
• Keywords: Proximity sensor; Tactile sensor; Microfiber; Electronic Skin

The monitoring of proximity-contact events is essential for human-machine interactions, intelligent robots, and healthcare monitoring. We report a dual-modal sensor made with two functionalized optical microfibers (MFs), which inspired by the somatosensory system human skin. integrated hierarchical structure gradationally detects finger approaching touching measuring relative humidity (RH) force-triggered light intensity variations. Specifically, RH sensory part shows enhanced evanescent absorption, achieving sensitive measurement fast response (110 ms), high resolution (0.11%RH), wide working range (10-100%RH). Enabled transition from guided modes into radiation waveguiding MF, force exhibits sensitivity (6.2%/kPa) (up to 1.5 kHz). By using real-time data processing unit, (PCS) achieves continuous detection full-contact events, including approaching, contacting, pressing, releasing, leaving. As proof concept, electromagnetic-interference-free PCS enables smart switch recognize proximity contact bare/gloved fingers. Moreover, skin respiration are realized. These initial results pave way toward category collaborative devices ranging interfaces multifunctional on-skin sensors.