Researchers from the Chinese Academy of Sciences have used a traditional Chinese folk art, called kirigami, to create 3D nanofabricated structures.
Macroscopic paper cuts in a paper sheet and nano-kirigami in an 80 nm thick gold film. (Source: Institute of Physics)
Kirigami is also called paper cuts or jianzhi. Kirigami involves cutting and folding flat objects into 3D shapes. For nanofabrication, the researchers were inspired by the traditional kirigami design called “pulling flower.” This kirigami method was used with flat films at the nanoscale. A focused-ion-beam (FIB) was used to cut the precise pattern in free-standing gold nanofilm and pull the nanopattern into a 3D shape.
There are two pulling forces that were introduced. Heterogeneous vacancies introduced tensile stress. The implanted ions introduced compression stress. There were many 3D shape transformations that were developed using this new method. These transformations include upward buckling, downward bending, complex rotation and twisting of nanostructures.
In the past, this type of nanofilm development focused on realizing the mechanical functions rather than the optical functions and also used difficult sequential methods. The kirigami method can be operated in a single fabricated step and focuses on the optical over the mechanical.
The 3D pinwheel-like structure with giant optical chirality was produced with the kirigami method. The newly produced nanostructure could reach the manipulation of both the “left-handed” and “right-handed” circularly polarized light with strong optical rotation effects. With this, the researchers could demonstrate a multidisciplinary connection between two fields of magnomechanics and nanophotonics.
The theoretical method was developed to clarify the dynamics of the nano-kirigami fabrication. The theoretical method allowed the researchers to design 3D nano-geometries that are based on the optical functionalities.
Nano-kirigami offers researchers and developers a 3D intelligent nanofabrication method that is completely different than the traditional methods, opening new doors for nanofabrication.
The paper on the kirigami nanofabrication method was published in Science Advances.
