A drive actuator for a measurement instrument having a probe, the drive
actuator including a heating element in a thermally conductive
relationship with the probe such that application of electric current to
the heating element modifies a characteristic of the probe. The probe
device includes a probe including a cantilever having a lever made of a
material having a selected thermal expansivity and a drive actuator in
operable cooperation with the cantilever lever made of a material having
a thermal expansivity different than the thermal expansivity of the
material of which the cantilever lever is made.