High-precision micronozzle fabrication

A process for fabricating a high-precision micronozzle with irregular inner shapes (at its end) and high aspect ratio (at its main part) was developed. Micronozzles 3 mm long with slit-type openings of 100×10 μm, triangular openings of 50 μm, and circular openings of 6 μm were successfully obtained. By using a WEDG (wire electrodischarge grinding) polishing technology, a core with a smooth mirrorlike surface was prepared, improving the precision and inner surface quality of the micronozzles produced. The core preparation process with WEDG and WECG can be carried out using common low-conductivity water. This makes the fabricating process simple and effective. Stainless steel was suitable as the core material for WECG operation. A micropipe with an inner diameter of 50 μm and aspect ratio of 40 was successfully manufactured without using parting film