  Exceptionally large strains can be produced in soft elastomers by the
application of an electric field and the strains can be exploited for a variety
of novel actuators, such as tunable lenses and tactile actuators. However,
shape morphing with dielectric elastomers has not been possible since no
generalizable method for changing their Gaussian curvature has been devised. It
is shown that this fundamental limitation can be lifted by introducing
internal, spatially varying electric fields through a layer-by-layer
fabrication method incorporating shaped, carbon-nanotubes-based electrodes
between thin elastomer sheets. To illustrate the potential of the method,
voltage-tunable negative and positive Gaussian curvatures shapes are produced.
Furthermore, by applying voltages to different sets of internal electrodes, the
shapes can be re-configured. All the shape changes are reversible when the
voltage is removed.
