Auxetic lattice architectures in additively manufactured Fe–Co alloys for enhanced inverse magnetostriction and energy harvesting

Powering the rapidly increasing number of Internet of Things (IoT) devices has become a critical challenge in recent years. Magnetostrictive energy harvesting has attracted considerable attention as a potential solution; however, the output of existing technologies remains insufficient for practical applications. In this study, a performance enhancement strategy based on geometric structural design is proposed. Fe – Co magnetostrictive alloys with multiple cubic-based lattice architectures were fabricated using laser powder bed fusion, and their energy harvesting performances were systematically compared. Under both impact and repetitive compressive loading conditions, the power generation performance consistently followed the order: Cubic-auxetic > Cubic > Bulk. Notably, the cubic-auxetic lattice achieved an output energy approximately 116 times higher than that of the bulk structure under an impact load of 500 N, demonstrating a viable pathway toward self-powered IoT devices and wireless sensors. This enhanced performance is attributed to a strengthened inverse magnetostrictive effect arising from local stress concentration and increased strain energy density induced by the lattice geometry. Moreover, the auxetic lattice reflects a bioinspired design principle observed in natural hierarchical structures. These results highlight geometric structural design as an effective and universal strategy for advancing magnetostrictive energy harvesting technologies to support the expanding IoT ecosystem.