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Soft actuators for real-world applications

Abstract

Inspired by physically adaptive, agile, reconfigurable and multifunctional soft-bodied animals and human muscles, soft actuators have been developed for a variety of applications, including soft grippers, artificial muscles, wearables, haptic devices and medical devices. However, the complex performance of biological systems cannot yet be fully replicated in synthetic designs. In this Review, we discuss new materials and structural designs for the engineering of soft actuators with physical intelligence and advanced properties, such as adaptability, multimodal locomotion, self-healing and multi-responsiveness. We examine how performance can be improved and multifunctionality implemented by using programmable soft materials, and highlight important real-world applications of soft actuators. Finally, we discuss the challenges and opportunities for next-generation soft actuators, including physical intelligence, adaptability, manufacturing scalability and reproducibility, extended lifetime and end-of-life strategies.

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Fig. 1: Working principles of tethered soft actuators.
Fig. 2: Working principles of untethered and biohybrid soft actuators.
Fig. 3: State-of-the-art soft actuators with potential industrial applications.
Fig. 4: Soft actuators in biomedical applications.
Fig. 5: Encoding physical intelligence in soft robot bodies.

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Acknowledgements

This work is funded by the Max Planck Society, the European Research Council (ERC) Advanced Grant SoMMoR project (grant number 834531) and the German Research Foundation (DFG) Soft Material Robotic Systems (SPP 2100) Program (grant number 2197/3-1). M.L., A.P. and A.P.-F. received the Humboldt Postdoctoral Research Fellowship and thank the Alexander von Humboldt Foundation for their financial support.

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M.L., A.P., A.A. and A.P.-F. contributed equally to this work. M.S. initiated the Review, and all the authors developed its outline. All authors contributed to the writing and editing of the Review.

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Correspondence to Metin Sitti.

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Li, M., Pal, A., Aghakhani, A. et al. Soft actuators for real-world applications. Nat Rev Mater 7, 235–249 (2022). https://doi.org/10.1038/s41578-021-00389-7

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