Shape memory alloys (SMAs) are smart materials with unique properties, including the one-way effect (1WE) and pseudoelasticity (PE) [1]. The 1WE enables shape recovery upon heating after up to 10% deformation and yields sustainable actuators, e.g., for switching, positioning or release mechanisms for various applications [2]. PE-SMAs play a crucial role in the medical field. PE-stents, which due to their high flexibility can be introduced through thin guide tubes, stabilize blood vessels. Moreover, PE-SMAs are used in both small- (e.g., unbreakable eyeglass frames) [ebd.] and large-scale (e.g., earthquake damping devices) products [3]. Recent studies even highlight the potential for cooling and heat engine applications [4,5]. Thus, SMAs emerge as a material class which not only directly fosters product sustainability, but also promotes the sustainable development (SD) of various industrial sectors by saving weight, energy, space, and resources (cf. SD-goals 7, 9, 11, 13) and/or enhancing aspects of health, safety, and circularity (cf. SDGs 3, 12, 15), cf. [6]. They also offer opportunities for various R-strategies to design intelligent and sustainable life cycles. To systematically explore the interplay between SMAs and SD, the present study focusses on three aspects: (1) Technological Solutions: Key findings are synthesized, focusing on the sustainability impact of SMAs utilized for innovative R-strategies and circularity. (2) Life-Cycle Engineering: Sustainability challenges and opportunities for the most successful SMA system to date, Ni-Ti, are examined in light of different production/processing strategies (e.g., ingot metallurgy, powder metallurgy, additive manufacturing). (3) Resources and Alloy Design: Ni-Ti-, Cu-, and Fe-based SMA systems are compared in terms of social, environmental, and economic KSIs, since the choice of the system at the beginning of the product life cycle plays a major role for key sustainability impacts (KSIs) of SMA technologies.

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