A driving device includes a first driving element and a first flexible structure. The first driving element includes a first wire extending in a first direction and includes a shape memory alloy. The first flexible structure has a certain width in a second direction perpendicular to the first direction, and when the first wire contracts in the first direction, the first flexible structure has a height increasing in a third direction perpendicular to both the first direction and the second direction. The driving device further includes a second driving element including a second wire and a second flexible structure, the second wire extending in the first direction and including a shape memory alloy. The second flexible structure has a certain width in the second direction, and when the second wire contracts in the first direction, the second flexible structure has a height increasing in the third direction.