Journal Article kirigami 63148-62-9 Dimethylpolysiloxanes Elastomers Research Support, Non-U.S. Gov't Review Smart Materials actuation baysilon bistability and multistability building energy saving directional buckling flexible electronics freestanding polymer nanosheets hierarchically cut hinges high work capacity magnetic soft composites mechanical metamaterials miniature wireless soft devices nonlinear and tailorable mechanical properties phase-change materials programmable shape deformation reconfigurable metamaterials soft actuating materials soft actuators soft robots stretchability stretchable metamaterials structural designs