Organic‐Nanometallic Versatile Printable Multifunctional Inks
Amritesh Kumar, Celia Rufo‐Martín, George YoussefABSTRACT
Advanced printable materials with intrinsically coupled mechano‐thermo‐magneto‐electric properties are essential for next‐generation wearable electronics and soft microscale robotics. Here, we report versatile printable magnetoelectric composite inks ( p ME‐inks) based on polyvinylidene fluoride (PVDF) and magnetic nanoparticles (Fe 3 O 4 or Ni), with the polymer‐to‐solvent ratio tailored to achieve stable shear‐thinning behavior without rheological modifiers. The resulting inks enable direct ink writing (DIW) of continuous, non‐porous, semi‐crystalline films while preserving the electroactive β‐phase without electrical poling or elaborate pre‐ or post‐processing. Incorporating magnetic nanoparticles enhances the thermomechanical stability of the printed films while maintaining high electrical resistivity and a measurable piezoelectric response. Remarkably, the unpoled composites exhibit direct magnetoelectric coupling, reaching 65 and 67 mV cm − 1 Oe − 1 in the in‐plane and out‐of‐plane directions, respectively, for 0.5 wt.% Ni, approximately fourfold higher than conventionally manufactured counterparts. The printed films further exhibit composition‐dependent magnetic attraction, deformation, and field‐induced morphing, demonstrating coupled mechanical and magnetic functionality. These results establish modifier‐free p ME‐inks as a versatile materials platform for room‐temperature additive manufacturing of multifunctional structures with intrinsically coupled mechanical, thermal, electrical, and magnetic responses, opening opportunities for soft microscale robotics, wireless power transfer, and energy harvesting.