Minimally invasive microsampler for intact removal of surface deposits and substrates

A method of sampling a multi-layered material having a top surface and a metallic or ceramic base comprising:

• penetrating a top surface of the material with a micro-cutting tool to a predetermined depth sufficient to include each layer of the multi-layered material and a portion of the base, without cutting through the full depth of the base;
• under-cutting from the depth of penetration through the base to define a micro-sample of the multi-layered material;
• and
• removing the micro-sample with each layer of the multi-layered material intact,
• wherein the top surface is curved and the penetrating and under-cutting are performed simultaneously through an arc of the curve,
• wherein the micro-cutting tool comprises an end mill,
• wherein the end mill comprises a major shank having a top end and a bottom end, a minor shank having a top end and a bottom end, the top end of the minor shank extending from the bottom end of the major shank, the major shank having a diameter larger than the diameter of the minor shank and together defining a central bore, and at least one cutter positioned at the bottom end of the minor shank, and wherein the step of penetrating the end mill comprises:
• rotating the end mill while penetrating the material to cut into the material to the predetermined depth;
• flowing a coolant downwardly through the central bore toward the material;
• undercutting through the material by moving the at least one cutter in a perpendicular direction relative to the bore sufficient to free the sample from the material, and simultaneously changing the direction of flow of the coolant upwardly through the bore towards the top of the major shank;
• and
• drawing the sample with the coolant flow through the bore upwardly through a filter for capturing the sample.