# Compliance

From Soft-Matter

The compliance of an object is the inverse of its stiffness. The stiffness of an object is intuitively obvious, that is, how much force does it take for a given deformation. This is similar to the elastic modulus (that is, the Young's modulus) however, the distinction is that the stiffness is a property of an object itself whereas the Young's modulus is a property of a material. In general, the stiffness is written as <math>k=F/\Delta x</math>, where F is a force applied to the object and <math>\Delta x</math> is the deformation imparted, be it a deflection, unidirectional extension or compression etc... The inverse of this, ie. <math>\Delta x / F</math> is the compliance, ie. How much deformation does one get for a given force.