Recent progress in single-phase molecular multiferroic materials with ferroelectricity and ferroelasticity

Single-phase multiferroic materials, characterized by the coexistence of ferroelectricity and ferroelasticity, have garnered significant attention due to the inherent coupling between polarization and strain. This coupling offers considerable potential for applications in multistate memory, high-sensitivity sensors and energy converters. Recently, molecular multiferroic materials have emerged as a research hotspot owing to their unique advantages, including structural diversity, facile tunability, mechanical flexibility, and environmental friendliness. Notably, these molecular multiferroics typically exhibit good mechanical flexibility and a pronounced response to applied stress, which facilitates the investigation of coupling effects between polarization and strain. However, existing reviews predominantly concentrate on a single ferroic property or specific material systems, resulting in a notable scarcity of systematic overviews of molecular multiferroic materials. This review aims to provide a comprehensive overview of recent progress relating to multiferroic materials that simultaneously possess ferroelectric and ferroelastic orders. We summarize key experimental findings, elucidate the relationship between molecular design strategy and material performance, and explore potential applications in flexible electronics, biomimetic sensing, and bio-integrated devices. This review is expected to shed new light on the future of this emerging field and promote cross-disciplinary cooperation and innovation in materials science, electronic engineering, biomedicine, and other related fields.