Cheng, ChuanChuanChengLührs, LukasLukasLührsKrekeler, TobiasTobiasKrekelerRitter, MartinMartinRitterWeissmüller, JörgJörgWeissmüller2019-10-162019-10-162017-07-27Nano Letters 8 (17): 4774-4780 (2017-08-09)http://hdl.handle.net/11420/3562Nanoporous metallic actuators for artificial muscle applications are distinguished by combining the low operating voltage, which is otherwise reserved for polymer-based actuators with interesting values of strain amplitude, strength, and stiffness that are comparable of those of piezoceramics. We report a nanoporous metal actuator with enhanced strain amplitude and accelerated switching. Our 3D macroscopic metallic muscle has semiordered and hierarchical nanoporous structure, in which μm-sized tubes align perpendicular with the sample surface, while nm-sized ligaments consist of the tube walls. This nanoarchitecture combines channels for fast ion transportation with large surface area for charge storage and strain generation. The result is a record reversible strain amplitude of 1.59% with a strain rate of 8.83 × 10-6 s-1 in the field of metallic based actuators. A passive hydroxide layer is self-grown on the metal surface, which not only contributes a supercapacitive layer, but also stabilizes the nanoporous structure against coarsening, which guarantees sustainable actuation beyond ten-thousand cycles.en1530-69842017847744780ACS Publ.Artificial musclecharge-induced strainelectrochemical actuationhierarchical nanoporous structurenanoporous metalPhysikTechnikJournal Article10.1021/acs.nanolett.7b01526Other