Fabrication of micro-structured parts by nanopowder printing using ES-nanofiber imprinting plastic mold

Abstract

This study aims to develop an eco-friendly fabrication method for micro-structured parts with high aspect ratio. To achieve this purpose, nanopowder printing (nPP) process was adopted to the plastic mold with microstructures produced by electrospinning nanofiber imprinting (ES-NFI) method. A novel method named as ES-NFI sacrificial plastic mold nanopowder printing (ES-NFI/nPP) was proposed and demonstrated in this study. Micro plastic molds were prepared by ES-NFI method using Si forms that have various micro-structures including line and space (L/S) pattern, multi-pillars and holes. The effects of aspect ratio in microstructure on the shape transcription were investigated by changing Si forms from 1µm to 50µm wide for 10µm high. Also the composition of paste materials made from TiO₂ nano-sized powder and PEG water-soluble binder was varied for the optimization. It was shown from the experimental results that the sintered part with microstructures of 50µm wide for 10µm high could be formed soundly, and it was also desirable to use the paste materials with lower content of binder polymer in keeping adequate viscosity. It was confirmed that ES-NFI/nPP method was a useful method for fabricating the micro-structured parts in the mass production.