Tough Environmentally Robust Cellulose Nanofiber-Reinforced Dual-Network Eutectogel with an Intelligent Self-Calibrating System for Human-Machine Interfaces

Hydrogels for next-generation human-machine interface (HMI) suffer from environmental instability and inconsistent signals, which limit their wearable deployment. We propose a comprehensive solution, spanning from material design to system integration, and develop a tough and environmentally tolerant dual-network conductive eutectogel. This gel introduces a deep eutectic solvent composed of choline chloride and acrylic acid as a multifunctional liquid phase, achieving high ionic conductivity (2.3 S/m), excellent antievaporation performance, antibacterial activity, and operational capability. A dual-network structure of poly(acrylic acid) and poly(vinyl alcohol) was synergistically reinforced with TEMPO-oxidized cellulose nanofibers, endowing the material with a tensile strength of up to 0.97 MPa and an elongation at break of 464%. To overcome challenges related to inconsistent signals among individual sensor variations, we developed an integrated multichannel self-calibration electronic system. The system actively calibrates and normalizes the signal from each sensor using an on-board digital potentiometer array and algorithm optimization. Based on the excellent performance of the material, the resulting multifunctional sensing platform enables visualization of different pressures, real-time gesture recognition, and control of the robotic hand. This work paves the way for the development of truly practical and highly reliable next-generation human-machine interfaces by integrating advanced material design with intelligent hardware engineering.