Fabrication of cylindrical micro-components using laser scan lithography and electrolytic etching of stainless steel pipes

A new fabrication method of cylindrical micro-components was investigated using laser scan lithography and electrolytic etching. First, net-like patterns were formed by repeating delineations of helical patterns crossing each other on fine pipes of stainless steel with an outer diameter of 100 μm and a wall thickness of 20 μm. The pipes were coated with 4-μm thick negative resist, and four couples of helical patterns were delineated for making the net-like patterns. Next, the pipes were etched in an aqueous electrolyte of sodium chloride and ammonium chloride. As a result, net-like pipes with multi-holes were successfully fabricated. Etched surfaces and sidewalls were smooth, and it was verified that the new method would be applicable to fabricating various cylindrical micro-components with hundreds of nanometer range roughness and accuracy. The technology will be particularly useful for developing special syringe needles, stents for supporting damaged blood vessels, and multi-hole tools for supplying air pressure to stent balloons.