Laser-Scan Lithography and Electrolytic Etching for Fabricating Meshed Pipes of Stainless Steel

Abstract

Numerous micro-slits were opened penetrating through fine stainless steel pipes using laser-scan lithography and electrolytic etching, and meshed pipes were fabricated. Such micro-fabrication technology will be useful for developing bio-medical micro-stents, syringe needles, mesh filters, and others. As original materials, stainless-steel pipes with an outer diameter of 100 μm, a thickness of 20 μm and a length of 40 mm were used. At first, each pipe coated with a positive resist was exposed to a beam spot of violet laser, and multi-slit patterns were delineated by scanning and intermittently moving the pipe in the axial and rotational directions. After the development, each pipe masked by the resist film except the slit pattern parts were etched individually. Electrolytic etching was applied by using an aqueous solution of NaNO₃ and NH₄Cl as an electrolyte. As a result, mesh structures composed of four linearly arrayed 22 slits arranged at every 90^o circumferential angle were fabricated.