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Linear
Positioners
Working Principle
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Working Principle - Coarse Positioners (ANP, ANR, ANG models)
Piezo Voltage
Piezoelectric actuator
Clamped table
AT REST
Guiding rod
Flexible membrane
Fixed frame
1
Piezo Voltage
Time
Flexible membrane supports
the piezo and the
axis
STICK
2
2. During the phase of the slow flank the clamped table
sticks to the guiding rod and is moved over a distance Δx.
The achieved expansion Δx is proportional to the applied
maximum voltage. The typical minimum step size for ANP
positioners is in the range of 50 nm at ambient conditions
and 10 nm at cryogenic temperatures.
3.
Time
∆x
Piezo Voltage
1. A guiding rod is firmly connected to a piezoelectric actuator while the moving table is clamped to it. A sawtooth
shaped voltage pulse is applied to the piezo.
net step is
completed
SLIP
3
By applying the steep flank of the voltage pulse to the
piezo, the guiding rod is accelerated very rapidly over a
short period of time, so that the inertia of the clamped
table overcomes friction. This way, the clamped table
disengages from the accelerated rod and remains nearly
non-displaced. The net step Δx is now completed.
Time
By repeating this procedure the table can be moved over
large distances with nanometer precision.
All ANS scanner units consist of a compact frame with
integrated flexure structures. Depending on the scanner
type, a set of suitable piezo stacks are implemented to
the frame. By applying unipolar DC voltages to the piezo
elements the piezo itself is expanded.
Working Principle – Scanners (ANS)
One-dimensional
z scanner
Two-dimensional
xy scanner
Three-dimensional
xyz scanner
The flexures amplify this motion and samples mounted
on an ANS scanner unit experience a scan motion much
larger than for bare standard PZT materials. The flexure
structures of all ANS scanners are optimized for large
scan ranges at cryogenic temperatures.