femtonewton [fN] Unit Converter

Definition of femtonewton [fN] unit

A femtonewton (fN) is a derived SI unit of force equal to one quadrillionth of a newton, or 10−15 newtons. It represents the force required to accelerate a one-kilogram mass at 10−15 meters per second squared.

History of femtonewton [fN] unit

The femtonewton derives its name from femto-, which denotes a factor of 10−15, and newton, the SI unit named after physicist Isaac Newton. The newton was formally adopted as an SI derived unit in 1948, while the femto- prefix was standardized within the International System of Units in 1960. Although not established as a separate physical unit, the femtonewton emerged naturally as scientists developed instruments capable of measuring extremely weak forces in molecular biology, nanotechnology, and precision physics. Its usage expanded with single-molecule manipulation and nanoscale force sensing.

Applications of femtonewton [fN] unit

Today, femtonewtons are used primarily in nanoscience and biophysics, where researchers measure interactions between molecules, biomolecular bonds, and microscopic surfaces. Optical tweezers, atomic force microscopes, magnetic traps, and advanced nanoelectromechanical sensors can detect or apply forces in this range. For example, scientists may quantify DNA stretching, protein folding, cell adhesion, or molecular motor activity.

Complete list of femtonewton [fN] unit conversion