Elinvar Materials: Recent Progress and Challenges

The Elinvar effect, characterized by an invariable elastic modulus with varying temperatures, drives technological innovation across diverse domains—from low‐modulus compliant actuators in soft robotics to high‐modulus protective shielding in aerospace applications. The scarcity of materials exhibiting the Elinvar effect while simultaneously meeting other practical requirements underscores the need for a comprehensive understanding of its underlying mechanisms. Although conceptually straightforward, the physical origins of the Elinvar effect remain complex and incompletely elucidated. This review explores recent progress in the field, distilling the key concepts underpinning leading contemporary Elinvar materials. We also discuss future prospects for these materials and outline the path toward achieving full control of a material's elastic modulus in response to thermal stimuli.