Coaxial Hydrogel Optical Fibre Skin for Interference-Free Multimodal Tactile Perception.

Area of Science:

• Materials Science
• Biomimetics
• Wearable Technology

Background:

• Flexible photonic fibers offer interference-free multimodal tactile sensing for wearables.
• Existing optical fibers lack mechanical robustness, signal decoupling, and environmental stability.
• System-level integration of such fibers remains a significant challenge.

Purpose of the Study:

• To develop a robust, integrated photonic skin for interference-free multimodal tactile sensing.
• To overcome limitations of existing hydrogel optical fibers in terms of mechanical properties and environmental stability.
• To create a wearable system with advanced tactile perception capabilities.

Main Methods:

• Fabrication of stretchable, refractive-index-matched core-cladding photonic fibers using continuous coaxial spinning and in situ photopolymerization.
• Development of a photonic skin inspired by jellyfish tentacles, routing pressure and temperature signals through independent photonic and ionic channels.
• Integration of the photonic skin with a flexible printed circuit and a machine-learning architecture for data processing.

Main Results:

• The photonic skin achieved high sensitivity and rapid response (sub-10-ms) for pressure and temperature sensing.
• The developed hydrogel fibers demonstrated mechanical stretchability, low optical loss, and robustness to temperature/humidity changes.
• The integrated wearable system achieved high accuracy in adaptive gesture recognition (99.21%) and multimodal object classification (99.22%).

Conclusions:

• The proposed photonic skin platform successfully bridges material-level signal decoupling with system-level multimodal perception.
• This technology offers a fully integrated solution for intelligent tactile interfaces in complex environments.
• The biomimetic approach provides a pathway for developing next-generation wearable sensory systems.