Superelasticity in micro/nanostructured materials

Abstract Achieving reversible strain greater than 1%, known as superelasticity, is highly desirable for practical applications across diverse fields, including medical care, transportation, and daily life. While conventional rigid materials, such as metals and ceramics, exhibit limited elastic deformation, advanced materials like amorphous alloys, high entropy alloys, and shape memory alloys demonstrate an enhanced elastic strain limit (≥1%) through mechanisms such as structural disordering, lattice distortion, or phase transformation. Further improvements in recoverable deformation can be achieved by incorporating micro/nanostructures into both conventional and advanced rigid materials. In this review, we systematically explore strategies for micro/nanostructuring rigid materials, including metals and covalent materials, to enhance their superelastic properties. Firstly, we examine the size effects on the elasticity or pseudoelasticity of rigid materials, with a particular focus on the superelastic behavior of small-sized materials. Secondly, we discuss how small-sized superelastic materials can serve as structural units to design geometrically complex micro/nanostructures and micro/nanocomposites, highlighting examples that exhibit exceptional reversible deformation capabilities. Finally, we review the potential applications of micro/nanostructured superelastic materials in nanotechnology and structural engineering, underscoring their transformative potential in these fields.