Strain Amplification\nStrategy for the Regulation of\n2D and 3D Optical Micro/Nanostructures

Three-dimensional (3D) nanostructures have attracted\nsignificant\nattention due to their excellent properties in electromagnetic field\nlocalization and regulation, which are hardly obtained from the planar\nnanostructure. Recently, a promising approach, internal or external\ntriggers induced by 2D precursor to 3D nanostructure transformation,\nhas emerged to provide a solid basis for studying and applying 3D\nmicro/nanostructures. However, the function and research of the constraint\nblocks in 2D precursors are still superficial, which restricts its\ndevelopment. Here, we have theoretically proposed and experimentally\ndemonstrated a strain amplification strategy for dynamically regulating\n2D and 3D optical micro/nanostructures. Arising from the restriction\nof the paired constraint blocks, the strain between the blocks is\nsignificantly increased to obtain a strain amplification effect, which\ncan be simulated by a finite element method (FEM), and verified experimentally\nfrom the gap change between the 2D gratings. Meanwhile, such a strategy\ncan regulate the 3D optical micro/nanostructures, such as the nanopyramids\nstudied here. The results indicate that the strain increment depends\non the design of the paired blocks, especially their length. Moreover,\nthe reflection properties of a nanorod dimer array were dynamically\nregulated by a combination of prestretching. The proposed strain amplification\nstrategy provides opportunities to regulate the 2D and 3D nanostructures\nfor active optical components, flexible electronics, and integrated\ncircuits.