
A particle with dimensions on the order of micrometers, often used in materials science.Microparticles are tiny objects with sizes ranging from about one micrometer (a thousandth of a millimeter) to a few hundred micrometers. At this scale, materials behave differently than in bulk: surface forces, electrostatic interactions, and shape-dependent packing become dominant. In materials science, microparticles are the building blocks of powders, granular materials, and many industrial products, from pharmaceuticals to 3D printing powders.
The systematic study of microparticles emerged with the development of microscopy and colloid science in the 19th century, but the term 'microparticle' became standard in the 20th century with advances in aerosol science and powder technology.
The behavior of microparticles is governed by a balance of forces that are negligible for larger objects. Gravity becomes less important, while van der Waals forces, capillary forces from moisture, and electrostatic charges take over. Shape matters enormously: irregular or faceted particles interlock mechanically, making piles more stable than those of smooth spheres. This is why a heap of shaped particles can defy easy collapse, as explored in studies of granular jamming.
Microparticles are used in drug delivery systems, where they control the release of active ingredients, and in the fabrication of metamaterials and photonic crystals, where their precise arrangement determines optical properties.
Raindrops can eject microparticles of plastic from the ground into the atmosphere, where they travel thousands of kilometers before falling elsewhere.




