Mechanical Strain‐Tunable Microwave Magnetism in Flexible CuFe2O4 Epitaxial Thin Film for Wearable Sensors

Flexible microwave magnetic CuFe 2 O 4 epitaxial thin films with large tunable in‐plane and out‐of‐plane ferromagnetic resonance spectra are demonstrated using purely mechanical strains (without electric‐driven). Purely mechanical strain‐tunable microwave magnetism devices, which are lightweight, flexible, and wearable, are promising for the application in flexible passive sensing systems and spintronic devices (noncontact).