substratewhere

Substratewhere is a term sometimes used in surface science and nanofabrication to denote the spatial locus on a substrate where a process, reaction, or observable event occurs or is measured. It serves as a descriptive coordinate that links experimental results to a precise position on the substrate rather than to a property of the bulk material.

The term is a portmanteau of substrate and where and is not part of a formal standard nomenclature in most fields. It is typically employed in discussions of thin-film deposition, patterning, catalysis on supports, and biosensor surfaces to specify the region of interest on a substrate where activity is attributed or data is collected. Because it is informal, its exact meaning can vary between studies and authors.

Determining substratewhere often involves spatially resolved techniques and careful record-keeping of coordinate systems. Common methods include optical or electron microscopy with positional mapping, localized spectroscopy, and registration to defined landmarks or grid marks. The goal is to correlate the observed phenomenon with a concrete, repeatable location on the substrate.

Applications of the concept include guiding pattern design in microfabrication, analyzing heterogeneity in catalytic supports, and documenting surface-bound interactions in sensors. However, due to its informal status, researchers are advised to define the substratewhere convention clearly when using it in publications to avoid ambiguity.

See also: substrate, surface science, localization, spatial mapping, patterning.