Muscle-Inspired Alignment Locking for Anisotropic Hydrogels with Multidirectional Stress Perception

Abstract Directional force resolution in flexible sensors is limited by material isotropy. Here, we report an anisotropic gelatin-based double-network hydrogel fabricated via synergistic alignment locking: uniaxial pre-stretching orients polymer networks and carbon nanotubes, while Hofmeister-mediated salting-out locks the structure via hydrophobic crosslinking. The longitudinal orientation provides robust mechanical scaffolding (933 kPa fracture stress), whereas the transverse orientation achieves exceptional stress sensitivity (45.98 kPa–1; 7.6-fold enhancement). This vectorized response enables mathematical force-vector calibration mapping (0–90°) via orthogonal multidimensional sensors. Combined with antifreezing ternary-solvent resilience (−26.2 °C), the system demonstrates real-time robotic control, advancing directionally aware flexible electronics.