Poisson’s ratio characteristics of mechanical metamaterials and their applications in flexible pressure sensors

Mechanical metamaterials, enabled by the rational design of architected geometries, offer unprecedented mechanical responses that transcend the limits of conventional materials, particularly in the programmable modulation of Poisson’s ratio. This review provides a comprehensive overview of the design principles and deformation mechanisms underlying negative, zero, and giant Poisson’s ratio metamaterials, encompassing representative topologies such as chiral lattices, re-entrant architectures, rotating polygon frameworks, and mesh-like networks, along with their corresponding fabrication strategies. Special emphasis is placed on the deployment of these unconventional Poisson’s ratio characteristics in flexible pressure-sensing systems. Negative Poisson’s ratio materials exhibit lateral expansion under tension and densification in compression, thereby amplifying strain-induced resistance variations and enhancing signal transduction. Zero Poisson’s ratio materials effectively suppress biaxial coupling and crosstalk, enabling high-fidelity multidimensional force perception. Giant Poisson’s ratio networks facilitate the construction of transparent, stretchable sensors with improved wrinkle resistance and mechanical robustness. Furthermore, the inherent conformability of mechanical metamaterials promotes intimate integration with complex, curvilinear surfaces, ensuring stable and reliable sensing performance across diverse operating conditions. Finally, this review summarizes significant challenges associated with the structural design, manufacturability, and device-level implementation of Poisson’s-ratio-programmable metamaterials, and outlines future research prospects toward next-generation flexible pressure sensors with enhanced precision, multifunctionality, and environmental adaptability.