Fabrication of Stainless-Steel Micro-Coils and Mesh Pipes using Lithography

Abstract

Precise micro-coils and mesh pipes with outer and inner diameters of 100 and 60μm were fabricated using laser-scan lithography and electrolytic etching. Non-magnetizable stainless-steel (SUS304) pipes were coated with resist films, and helical patterns were delineated using a laser-scan exposure system. Positive resist PMER P-LA900 was used for fabricating micro-coils, and negative resist PMER N-CA3000 was used for fabricating micro-mesh pipes. Mesh patterns were formed by doubly delineating helical patterns coiled in opposite directions each other. Widths of resist patterns used for fabricating mesh patterns were also controlled by stitching two helical patterns. Because space widths of coils and sizes of mesh holes became larger than space widths and hole sizes of resist patterns caused by undercut in etching process, widths of resist patterns were adjusted by considering the undercut depths. As a result, pipe specimens were suitably etched in a solution of sodium chloride and ammonium chloride in water, and micro-components with homogeneous widths were successfully fabricated.