Futamura's deformation index n can be defined as follows. p is the parameter whose value is controlled (i.e., held constant). E is
Young's modulus of
linear elasticity. \epsilon is the strain. \sigma is the stress. : p= \epsilon E^{ \frac{n}{2}}= \sigma E^{ \frac{n}{2}-1} Particular choices of n yield particular modes of control and determine the units of p. For n=0, we get strain control: p= \epsilon = \sigma E^{ -1}. For n=1, we get energy control: w = \frac{1}{2} p^2 = \frac{1}{2} \epsilon^2 E= \frac{1}{2} \sigma^2 E^{ -1}. For n=2, we get stress control: p= \epsilon E= \sigma . ==History==