Non-uniform Kirigami Enhances Films Conformability

Developing films with great conformability has become a research hotspot in many fields. The conventional method to enhance conformability is to make the film thinner and more compliant, which usually compromises the strength of the structure. For example, developing functional medical bandages that can perfectly conform to the skin surface during cyclic bending of the joints is still a considerable challenge. In this paper, we propose a novel non-uniform kirigami to make the film achieve the same non-uniform auxetic (negative Poisson's ratio) deformation as the skin around the joint area. By mapping the corresponding unit cells to the target surface, the surface can easily achieve the same deformation as the target skin without any alterations in its thickness or adhesion. As the obtained non-uniform kirigami film structure has the same deformation behavior as the target skin surface, the conformability of the structure can be guaranteed during the entire rotation process of the joints. Moreover, the proposed film is also expected to be used in novel biomaterials, such as smart bandages, skin scaffold, etc.