A bendable apparatus is provided. The flexible material has a first-surface spanned by a first direction and a second direction. The bendable apparatus also includes a first-constraining surface one of: formed in the first-surface of the flexible material; or attached to the first-surface of the flexible material; and a piezo-electric element including a first-edge surface and a second-edge surface opposing the first-edge surface. The piezo-electric element is fixedly attached on the first-surface of the flexible material, so that: the first-edge surface and the second-edge surface are at least approximately perpendicular to the first-surface of the flexible material, and the first-constraining surface is adjacent to the first-edge surface of the piezo-electric element. When a voltage is applied to the piezo-electric element, the piezo-electric element expands in length, the first-edge surface of the piezo-electric element applies a force on the first-constraining surface, and the flexible material bends.