Synthesis of black magnetic electrophoretic particles for magnetic-electric dual-driven electronic paper

The application of electronic paper (e-paper) is now propelling the development of the multifunctional e-paper products. There is an extraordinary diversity of basic and applied research in pursuit of the novel e-paper. Here, we report the first achievement of a magnetic-electric dual-driven e-paper, using black magnetic electrophoretic particles (BMEPs). BMEPs are synthesized via a facile, green, low-cost, one-step method. By adjusting the reaction conditions, the density, surface, and magnetic properties of the BMEPs are optimized for e-paper display. Finally, the e-paper display is successfully assembled using dispersion of the BMEPs in a mixed dielectric solvent with white particles as contrast. Thanks to the magnetic properties and a positively charged surface, the BMEPs can be driven by both electric and magnetic fields. The prototype display is fabricated whose switch is achieved by the application of either a bias voltage of 10 V or a magnetic bias. The as-prepared magnetic-electric dual-driven device could have many promising applications in the field of anticounterfeiting labels for secure identification documents.