Imprint process with in-plane compression method for bio-functional surface

Abstract

In this research, we propose an in-plane compression imprint method as a further development of the special micro patterning method to realize various biomimetic functional surfaces. Biomimetic is popular in the field of engineering in recent years. We focused on biomimetic functional surfaces of natural organisms. For example, micro scales on the wing of a morpho butterfly develop a bright blue color. The scales have specific dendrite-like nano-structures. We aim to mimic such functional surfaces by nano imprint lithography (NIL). NIL has high resolution and high productivity, and is known as a technology that can be applied to various materials. Conventional NIL requires mold release in the process, so it is difficult to form special shapes such as the overhang shape. To solve this problem, we propose an in-plane compression process. In our new process, work materials were imprinted on a stretched silicone film, and imprinted materials were compressed by in-plane compressive stress due to the elastic recovery of the silicone film. In this paper, we show some examples increasing the aspect ratio more than twice by the proposed process. We also show a strategy to form a complicated morpho’s surface pattern with an overhang structure having a high aspect ratio.