Hybrid platinum/single-wall carbon nanotube nanowire actuators: metallic artificial muscles

In this paper, we report that reversible strain amplitudes that are three times higher than commercial piezoceramics can be achieved in metallic nanowire actuators. By self-assembling nanoparticles of platinum on single-wall carbon nanotube templates, hybrid nanowires of platinum were fabricated with extremely high surface area to volume ratio. These nanowires showed reversible strains of 0.3% by modulating the surface electronic charge density through an applied potential relative to an electrolyte. Three regimes of actuation corresponding to different actuation mechanisms at different charge injection levels were identified. A stress of ~12 MPa was generated, corresponding to the maximum strain of 0.31% at low voltages. These results show the applicability of hybrid metallic nanowire systems for artificial muscle applications.