Movie S1.

Time-lapse video showing the morphing carbon fiber material deforming on application of a current. 1 second of video corresponds to 15 minutes in real time. First a current density of 44.18 mAg^-1 is used causing a fast deformation, with a maximum tip displacement of 14.4 mm, and secondly 14.5 mAg^-1, with a maximum tip displacement of 35 mm. 1-hour of no current is applied between applications of current to allow ion concentrations to equilibrate. Here the cantilever length is 48 mm, with average cross section of the carbon fiber layers of 53.4 μm and of the separator 21.0 μm.