MECHANICS OF ADHESION - Nanoindentation with Biological Applications - page 82

Figure 4-4. The variations in the full potential, force, and stiffness (solid lines) with tip
position for combined logarithmic and harmonic potentials (dotted lines) for an imposed
tip position at the critical tip-surface separation, such that there is one possible
equilibrium tip position. The values are normalized using the characteristic values
( Eq. 4-9 ).