Form Factor–Free Magneto-Triboelectric Generator for Standalone Power Line IoT Applications

The growing reliance on electronic devices has made ambient magnetic field harvesting a promising solution for powering low-power, small-scale technologies, such as those used in the Internet of Things (IoT). While metal alloy-based magneto-deformation materials have traditionally been used to capture energy from stray magnetic fields, they are costly and lack versatility. To advance magnetic field harvesting, it is essential to develop cost-effective, high-performance, and adaptable magneto-deformation materials. Incorporating ferromagnetic metal powders into polymers can induce magneto-rheological behavior. This quasi-solid magneto-rheological effect enables the generation of mechanical vibrations in response to an oscillating external magnetic field. Here, a functional composite film is presented that achieves efficient and straightforward magneto-deformation by integrating Fe powder with poly(vinylidene fluoride-trifluoroethylene). To further enhance the performance of the composite film, MoS₂–SiO₂ core–shell nanoparticles is exploited for improved charge trapping and employ ferroelectrics to increase the contact potential difference (CPD). The composite film shows a bending displacement of 1 mm in a 4 Oe magnetic field, with each magneto-triboelectric module generating 14.28 mW. The four fabricated modules successfully harvest real-time energy from the stray magnetic field of an electric pot, enabling a battery-free Bluetooth IoT sensor.