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

Area of Science:

• Biomimetic sensors
• Optical physics
• Materials science

Background:

• Proximity-contact event monitoring is crucial for human-machine interaction, robotics, and healthcare.
• Existing sensors often lack the sensitivity or multi-modal capabilities for comprehensive detection.

Purpose of the Study:

• To develop a dual-modal optical microfiber sensor inspired by the human somatosensory system.
• To achieve sensitive and continuous detection of proximity and contact events.
• To demonstrate applications in smart switches and healthcare monitoring.

Main Methods:

• Fabrication of a dual-modal sensor using functionalized optical microfibers.
• Integration of relative humidity (RH) and force sensing capabilities.
• Utilizing evanescent absorption for RH detection and mode transition for force detection.
• Real-time data processing for continuous event monitoring.

Main Results:

• The RH sensor demonstrated high sensitivity (0.11%RH resolution) and a fast response (110 ms) over a wide range (10-100%RH).
• The force sensor achieved high sensitivity (6.2%/kPa) and a fast response (up to 1.5 kHz).
• The proximity-contact sensor (PCS) successfully detected full contact events and enabled a smart switch system.
• Demonstrated skin humidity and respiration monitoring capabilities.

Conclusions:

• The developed optical microfiber sensor offers a promising platform for advanced human-machine interfaces.
• The biomimetic design enables multifunctional sensing for diverse applications, including healthcare.
• This technology paves the way for a new generation of optical collaborative devices.