Piezoelectric actuator
Clamped ta
3 SLIPPING PHASE
AT REST
Time
working principle stepping
positioners
STICK
AT REST
1
Piezoelectric actuator
Time
∆x
net step is
completed
3
Time
1
The moving table is spring-clamped to the
driving element moved by a piezoelectric
ceramic. The clamping force and the
coating on both sides of the frictional
contact have been carefully chosen for
the respective environment. There is no
voltage applied to the piezo, the table is
held in place by the friction with the driv-
ing element.
2
A sawtooth shaped pulse is applied to
the piezo. During the phase of the slow
flank the movable table sticks to the drive
element and is moved over a distance Δx.
The achieved expansion Δx is proportion-
al to the applied maximum voltage. The
typical minimum step size for positioners
is 50 nm at room temperature and about
10 nm at cryogenic temperatures.
By repeating this procedure the table can be moved over large distances with nanometer precision.
3 By applying the steep flank of the voltage
pulse to the piezo, the drive element is
accelerated very rapidly over a short period
of time, so that the inertia of the movable
table overcomes friction. This way, the
table disengages from the accelerated
drive element and remains nearly non-dis-
placed. The net step Δx is now completed
and the table remains fixed again at zero
voltage.
attoMOTION
Piezo-based Nano Drives