Multistable structures for large-scale applications

Abstract Bistable and multistable structures are systems capable of reaching two or more stable configurations. They have emerged as foundational elements in adaptive engineering, soft robotics, energy harvesting, and deployable architectures. This review seeks to highlight challenges related to scalability and practical implementation of multistable systems, focusing on addressing these challenges through identifying innovative mechanisms, fabrication methods, material selections, and system design strategies, with the overarching goal of charting a comprehensive roadmap for future research. We begin by clarifying key definitions and by delineating the fundamental concepts of stability and energy landscapes. Next, we classify existing systems into geometrically induced bistability, material-induced multistability, and mechanismbased and compliant structures, and provide a discussion on the scalability of multistable mechanisms. We then examine advances in additive manufacturing and material selection that enable precise control of energy barriers and switching forces across scales. Representative applications in logic and memory devices, soft robotics, energy harvesting and vibration control, wave control, smart architectural elements, and deployable and morphing structures, are highlighted to illustrate the multifunctionality afforded by bistable and multistable behavior. Finally, we discuss challenges and opportunities in the scaling-up of multistable systems, with focused discussions on durability and design methods, and provide thoughts on a path to producing large-scale multistable structures.