Designing three-dimensional polymeric structures using capillary wetting on colloidal monolayer

Abstract

Colloidal lithography is a technique that uses colloidal nanoparticles as a mask to create a regular pattern or structure, which can be used to create a regular pattern. A plasmonic color may be realized by depositing a metal on a regular pattern made by using colloidal lithography, and a hydrophobic waterproof surface may also be manufactured by increasing the contact angle with water while changing the shape of the pattern. This research designed a new type of three-dimensional polymer structure using the wetting phenomenon that occurs in the colloidal monolayer. The silica particles used in this research are embedded in the resist by capillary wetting until a contact angle with the resist is reached, but if the amount of resist is very insufficient, the resist is not embedded but rises on the silica particles. Various characteristics were analyzed by designing a new type of 3D polymer structure that did not exist before using this phenomenon. The contact angle of the resist SU8-2 used in this study with water was about 40 degrees, and the contact angle of the 3D nanostructure made using the SU8-2 increased to a maximum of 135 degrees. In addition, when aluminum was deposited on this nanostructure, a plasmonic color appeared, and a color change was induced by changing the structure. The biggest advantage of this research is that it is possible to create a nanostructure with a high contact angle and implement a plasmonic color using only a minimum resist without post-treatment.