micronewton

The microNewton (symbol μN) is a unit of force in the International System of Units (SI). It represents one millionth of a newton, since 1 μN = 1 × 10^-6 N. The micro prefix indicates a very small force, and the unit is used in contexts where forces are too large to be measured conveniently in nanonewtons or too small for millinewtons.

One microNewton is also equal to 1,000 nanonewtons (nN), because 1 N = 1 × 10^9 nN. In terms of mass under Earth's gravity, a force of 1 μN corresponds to the weight of a mass of about 1.0 × 10^-7 kilograms (roughly 0.1 milligram).

Applications and usage often arise in micro-scale engineering and science. MicroNewtons are encountered in microelectromechanical systems (MEMS), microactuators, micropositioning devices, and precision force measurements at small scales. They may be used to express forces acting on microstructures, adhesion measurements, or surface interactions where larger units would be impractical.

Measurement and calibration of microNewton-scale forces typically employ sensitive force sensors, including capacitive, piezoresistive, or optical readouts, and calibration methods such as electrostatic or thermal standards. In research instrumentation like atomic force microscopes, forces are often reported in the piconewton to nanonewton range, while μN scales appear in related microfabricated devices or macro-handler interactions with small components.

See also: Newton, nanonewton, micronewton prefix, SI units of force.