microtomillimeter

Microtomillimeter is a descriptive term used to refer to dimensions that lie between microscale and millimeter-scale features. It is not a formal SI unit or standardized name. In practice, it appears in engineering, microfabrication, and rapid prototyping to indicate intermediate sizes that are larger than typical microfeatures but smaller than conventional macro parts.

Range and interpretation. The term is used variably, but it commonly covers roughly 1 micron to about 1 millimeter, with some authors extending to a few millimeters. The exact boundary depends on context, especially manufacturing method and measurement capability.

Measurement and tolerances. Metrology for this scale uses high-resolution optical microscopy, profilometry, atomic force microscopy for fine surface detail, or 3D scanners; for larger parts, coordinate measuring machines or laser trackers. Tolerances are process-dependent and can range from sub-micron to a few tens of micrometers in typical microfabrication, with surface finish also playing a critical role.

Applications and examples. The microtomillimeter range is relevant for microfluidic channels (tens to hundreds of micrometers wide), micromachined mechanical components (gears, springs, hinges in the 0.1–2 mm size), compact optical elements (micro-lenses, waveguides) and components designed for handheld or portable devices that require fine features on a small scale.

Terminology and usage notes. Because there is no formal definition, readers should rely on context to interpret the range. The term is most useful as a shorthand for design and manufacturing discussions that span micro and small macro scales, rather than as a standalone measurement unit. Alternatives include 'sub-millimeter' or explicit size ranges (e.g., 1 μm–1 mm).