A Multifunctional Eutectogel for Wide‐Temperature and Intelligent Speech Recognition

ABSTRACT The practical application of flexible sensors is often constrained by limited mechanical properties and a narrow operating temperature range, particularly under subzero conditions. Herein, a multifunctional eutectogel is fabricated via one‐step thermal polymerization of methacrylic acid and functionalized adenine in a binary solvent system comprising water and a deep eutectic solvent (DES). This gel exhibits high strength, remarkable fatigue resistance (withstanding 10 000 electrical cycles), and stable performance across a broad temperature range. By leveraging hydrophobic domains and a multi‐physical crosslinking strategy, a synergistic balance between mechanical flexibility and structural stability is achieved. The hydrophobic structures are mainly contributed by hydrophobic interactions, π–π stacking, hydrogen bonding, and electrostatic interactions, while the flexible hydrophilic network incorporates multiple physical interactions, endowing the material with outstanding mechanical properties. The eutectic network formed in the binary solvent system enables reliable operation across a wide temperature range (−20°C to 80°C). As a multifunctional sensor, it accurately monitors human motion and functions as a bendable supercapacitor, retaining a high areal capacitance of 495 mF·cm ⁻² and 94.8% capacitance after 1400 charge–discharge cycles. When integrated with a deep learning algorithm, the system enables real‐time data processing and multilingual speech recognition, demonstrating considerable potential for next‐generation wearable electronics.