Variable stiffness actuators: review on design and components

Sebastian Wolf, Giorgio Grioli, Oliver Eiberger, Werner Friedl, Markus Grebenstein, Hannes Höppner, Etienne Burdet, Darwin G. Caldwell, Raffaella Carloni, Manuel G. Catalano, Dirk Lefeber, Stefano Stramigioli, Nikos Tsagarakis, Michaël van Damme, Ronald van Ham, Bram Vanderborght, L.C. Visser, Antonio Bicchi, Alin Albu-Schäffer

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    264 Citations (Scopus)
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    Variable stiffness actuators (VSAs) are complex mechatronic devices that are developed to build pas- sively compliant, robust, and dexterous robots. Numerous different hardware designs have been developed in the past two decades to address various demands on their functionality. This review paper gives a guide to the design process from the analysis of the desired tasks identifying the relevant attributes and their influence on the selection of different components such as motors, sensors, and springs. The influence on the performance of different principles to generate the passive compliance and the variation of the stiffness are investigated. Furthermore, the design contradictions during the engineering process are explained in order to find the best suiting solution for the given purpose. With this in mind, the topics of output power, potential energy capacity, stiffness range, efficiency, and accuracy are discussed. Finally, the dependencies of control, models, sensor setup, and sensor quality are addressed.
    Original languageUndefined
    Pages (from-to)2418-2430
    Number of pages13
    JournalIEEE/ASME transactions on mechatronics
    Issue number5
    Publication statusPublished - Oct 2016


    • EWI-27222
    • IR-101452
    • METIS-318520

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