Over 0.1 W root-mean-square output achieved in magneto-mechano-electric generators using Mn-doped PIN-PMN-PT single crystals.

The rapid growth of the Internet of Things infrastructure requires scalable and autonomous power solutions, as traditional battery and cable-based methods are impractical. Magneto-mechano-electric generators, which harvest ambient magnetic fields, present a promising alternative, though further research is needed to optimize their materials and designs for widespread deployment. In this study, we present a high-output magneto-mechano-electric generator utilizing Mn-doped single-crystalline Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) grown by the modified Bridgman method. The integration of Mn acceptor ions into the crystal structure significantly enhances the mechanical quality factor, which is crucial for efficient energy harvesting. Finite element analysis simulations were conducted to estimate the impact of acceptor doping on the performance of the magneto-mechano-electric generators. The Mn-doped magneto-mechano-electric generator achieved a root-mean-square power output of 106.2 mW under an induced alternating current magnetic field of 7 Oe, which is nearly 2.2 times higher than that of the undoped generator. The calculated root-mean-square power density of 35.8 mW/cm³ is approximately 8 times higher than that of the recently reported hybrid-type magneto-mechano-electric generator. The practical application of the Mn-doped harvester was demonstrated by powering multiple multifunctional Internet of Things sensors, including in a battery-free configuration. Real-time environmental monitoring data were successfully transmitted to smartphones, highlighting the potential of acceptor-doped piezoelectric PIN-PMN-PT crystals in developing high-performance, sustainable, and battery-free energy harvesting solutions, paving the way for their integration into a wide range of Internet of Things applications.