submicron

Submicron refers to sizes smaller than one micrometer (1 μm). The term describes particles, features, or structures whose characteristic dimension falls below one micron and is widely used across science and engineering to indicate a scale between the nanoscale and the micro-scale.

In aerosols, submicron particles are typically defined as particles with diameters less than 1 μm. They can remain suspended in air for extended periods and may be inhaled, with deeper lung penetration than larger particles. In materials science, submicron refers to particles or grains whose size is in the submicron regime, often 1 μm or smaller, which enhances surface area and reactivity.

Measurement and characterization employ a range of tools. Electron microscopy (scanning and transmission) provides direct imaging down to submicron and nanometer scales. Dynamic light scattering and nanoparticle tracking analysis estimate sizes in suspensions, while X-ray diffraction can infer crystallite sizes in the submicron range.

Applications cover submicron features in semiconductor fabrication, where circuit patterns are produced with submicrometer dimensions, and in microelectromechanical systems (MEMS). Submicron powders and nanoparticles are used as catalysts, adsorbents, and in energy storage materials, reflecting the high surface area of small particles.

Challenges include preventing aggregation, achieving reproducible synthesis, and ensuring safe handling due to inhalation risks. Metrology for submicron materials requires careful calibration and dispersion control to obtain reliable size distributions.

Submicron is a descriptive term that encompasses a variety of materials and processes, serving as a bridge between nanomaterials and larger microstructures.