When the bonding force varies
below 300 mN, the dependence of the contact area on the
bonding force is similar to that of the shear force. Both
the contact area and the shear force increase with increasing
bonding force. There is a certain value for the shear
force beyond which the shear force gradually changes with
the bonding force, while the contact area keeps increasing
through the whole range of the bonding force. Obviously,
a larger contact area does not necessarily give rise to a
larger shear force