Graphene-based flexible magnetic tactile sensor with vertically periodic magnetization for enhanced spatial resolution 

This study presents the design and implementation of a fully flexible, high-resolution magnetic tactile sensor that integrates a vertically periodic magnetized magnetic film with a 3 × 3 flexible Hall sensor array. To achieve optimal mechanical flexibility and electrical performance, graphene was employed as the active sensing material, and polyethylene terephthalate (PET) was chosen as the substrate, based on a comprehensive evaluation of carrier mobility, material thickness, mechanical compliance, and fabrication compatibility. The incorporation of a vertically periodic magnetization strategy in the magnetic film effectively suppressed lateral magnetic field interference and improved surface magnetic flux concentration. This architectural approach enabled spatial position recognition to be enhanced from 3 × 3 to 6 × 6 sensing units. The fabricated sensor exhibited robust performance, achieving an average sensitivity of 0.13 mV/N, a linearity coefficient of 0.97, and a hysteresis rate of 11.4%, demonstrating its potential for high-performance tactile sensing in flexible electronic systems.