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

These limitations are addressed by employing iron, one of the most abundant materials on Earth, and the flexible ferroelectric polymer P(VDF-TrFE). The composite film of P(VDF-TrFE) and iron exhibits mechanical deformation under magnetic fields, combined with excellent flexibility, cost-effective fabrication, and straightforward processing. These properties enable its integration with triboelectric technology, offering potential for diverse applications in energy harvesting and beyond.

Abstract

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.