interstices

Interstices are small spaces or gaps between components of a larger structure. The term is from Latin interstitium, meaning “between (the) standing parts.” It is used across disciplines to denote narrow openings, crevices, or intervals where elements meet or interact.

In crystallography and materials science, interstitial sites are positions in a crystal lattice occupied by atoms that fit into spaces between larger host atoms. In close-packed metals, tetrahedral and octahedral interstices accommodate smaller atoms such as carbon, altering strength, hardness, and diffusion. Interstices also define pore spaces in porous materials, influencing porosity and transport properties.

In architecture, construction, and textiles, interstices refer to gaps between elements—between bricks, panels, or fibers. These spaces affect ventilation, drainage, moisture management, and light transmission. Interstices can be intentional design features or sources of unwanted leakage or structural movement.

In biology and medicine, interstitial spaces lie between cells within tissues; the interstitium comprises these spaces and the interstitial fluid that bathes them. Interstices support exchange of nutrients and signaling molecules and can participate in edema, inflammation, and tumor spread when fluid dynamics are altered.

The term is also used metaphorically in philosophy and urban theory to denote interfaces or liminal zones between systems, disciplines, or cultures, where contact occurs but boundaries remain.