| Here, the order of magnitude
of the dimensions involved is at the one nanometer scale. Flatness
to this precision is entirely inaccessible to roller or ball bearings.
EDM wire cut frictionless flexures are the only feasible options. However
the demands on these flexure systems are enormous. The commonly deployed
‘simple parallelogram flexures' are subject to cosine errors and so cannot
be exploited. Designing complex guiding systems eliminate this error. However,
even the most perfectly constructed flexures only function in practice
when mechanical errors in the manufacturing process are reduced to a minimum. |
Of particular interest is
the introduction of the driving force. Forces with a single degree of freedom
that are absolutely parallel to the plane of motion are crucial as just
tiny errors in angle lead to trajectory tilting.
PI’s phenomenal experience in constructing nanomechanical
parts was mobilized to meet this difficult challenge. We have developed
over a hundred different nanopositioning systems down the past 20 years.
Our performance-proven expertise and resources were pooled together to
design and develop the device depicted in Fig. 12, i.e., the P-731K022
nanopositioning stage. By using capacitive sensors, the unit provides sub-nanometric
resolved travel, stability through a 100 x 100 µm travel range and
flatness in the nanometric region (Fig. 13).
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