• • The sensor achieves a linear response to normal forces from 1 to 25 N with R²=0.99, ensuring reliable force magnitude measurement across a wide operational range.
• • Stable sensitivity for shear forces within 0–4 N enables accurate detection of force direction, critical for multidimensional input and tactile perception.
• • The sensor's piezoresistive mechanism based on ionic hydrogels offers a simple structure and mature fabrication, facilitating integration into flexible electronic systems.
• • Demonstrated application in a flexible password security system expands traditional 1D password input to multidimensional formats (numeric, alphabetic, Morse code), enhancing information security.