Spin transfer torque memory cells and methods of forming the same are described herein. The test heads are respectively disposed on a first robot and a second robot, in each case in a freely movable manner, with at least one degree of freedom, such that they are aligned coaxially in relation to each other and perpendicular to a surface of a workpiece. By so doing, live tiles may be presented more safely, faster, or using fewer resources. The number of unique numeric identifiers is equal to the number of patterns, and the size of each unique numeric identifier is substantially smaller than the field of each pattern. The structural filler used is typically ground to a mean particle size of less than 0.