Manipulation of Fractal Nano‐Kirigami by Capillary and Electrostatic Forces

Abstract

Fractals are beautiful forms of geometric patterns, usually having high degrees of freedom of shape change. Recently, fractal and fractal‐like designs have aroused great interest in scientific research. Here, fractal‐like nano‐kirigami structures with rotational symmetries are proposed and demonstrated, in which topological morphologies can be transformed by growing fans and coiling units. Experimentally, the nano‐kirigami structures with different fractals are manipulated by using the capillary force‐induced 3D deformation process. Benefited from the fractal‐like designs, the structral deformations exhibit strong fractal dependence, with which the stress threshold and reflection spectrum can be tailored by changing the number of fans and coiling units. The modulation of fractal nano‐kirigami is further demonstrated by using the electrostatic forces when external voltage is applied. The fractal nano‐kirigami structures are also envisioned with capability of conveniently generating fractal‐dependent optical vortices. The special fractal design strategy in this work can bring new opportunities to functional 3D micro/nano structures with improved optical tunability and customization.

Optoelectronically navigated nano-kirigami microrotors

“…In recent years, with the rapid development of micro/nanofabrication technologies, the concept and design of kirigami have been extended to the scientific research in the microscopic world. The key significance lies in that nanoscale kirigami structures (named nano-kirigami) can support integrable 3D morphological transformations upon exposure to external stimuli in microscale, such as mechanical (20), thermal (21), electric (22), and magnetic (23) fields, leading to fundamental breakthroughs and useful applications in biomolecular engineering (24,25), chirality research (26)(27)(28)(29), and nanophotonics (22,27,(29)(30)(31). Therefore, creating versatile nano-kirigami structures with reconfigurable and transformable topology has become a prominent research objective.…”

Broadband and high-efficiency polarization conversion with a nano-kirigami based metasurface

“…Nano-kirigami metasurfaces 1 , which are composed of polymorphic subwavelength artificial nanostructures based on versatile shape transformation methods, not only bring new degree of freedom to the traditional three-dimensional (3D) nanomanufacturing, but also exhibit extraordinary potentials in the field of reconfigurable holograms 2 , 3 , fractal-dependent optical vortices 4 , Fano-resonant metamaterials 5 – 7 , reversal of circular dichroism 8 , 9 , and so on. Particularly, nano-kirigami 1 , 10 , 11 could enable sophisticated shape changes from the two-dimensional (2D) precursors to 3D deformed nanostructures with vertical displacement, spatial bending, which provides a novel approach to manipulate the amplitude, phase, and polarization of electromagnetic waves in the microscale/nanoscale region.…”