Method of providing microscopic features

A method of forming microscopic features on the inside surface of a metal engine cylinder liner comprising the steps of:

• coating a portion of the inside surface with a photo-sensitive material;
• treating portions of the material by directing a collimated beam of light onto the material and moving the inside surface of the cylinder liner and the beam relative to each other so that the selected portion of the material forms a first pattern and further forms a second pattern;
• removing the treated portions of the material to thereby reveal portions of the inside surface corresponding to the first and second patterns;
• and
• etching the inside surface to thereby form microscopic features the microscopic features having a depth between about 3 μm and about 15 μm, the microscopic features following the first pattern and the second pattern, the first pattern having a first density of microscopic features and the second pattern having a second density of microscopic features.

A method of forming microscopic features on the inside surface of a liner for the cylinder of an engine comprising the steps of:

• coating a portion of the inside surface with a photo-sensitive material;
• treating a selected portion of the material by directing a collimated beam of light onto the material;
• moving the inside surface and the light beam relative to each other so that the selected portion defines a pattern extending laterally about the inside surface;
• removing the selected portion to thereby to leave an opening through the material generally corresponding to the pattern;
• etching the inside surface through the opening along the pattern to thereby form a microscopic feature following the pattern on the inside surface, wherein the etching step includes the step of controlling the depth of the microscopic feature to a desired depth between about 3 μm and about 15 μm.