Asymmetric fluid-structure dynamics in nanoscale imprint lithography

Figure 3.7 Initial and final desired orientation with three-point controlBased on these motion requirements, Physik Instrumente M-222.50 DCMike actuators were selected. This actuator has a travel range of 10 mm with adesigned encoder resolution of 8.5 nm; the encoder ratio is 118,567.90counts/mm. However, the minimum incremental motion is 50 nm. Each actuatoris capable of 100 N (22.5 lbs) of force. An optional piezoelectric actuator, whichwould fit at the tip of the DC Mike actuator, is being considered for extremelyhigh resolution, high force output. The piezoactuator’s resolution would bedependent on the number of bits of a D/A converter as well its travel range. Theactuators are controlled by a closed-loop DC motor controller. PhysikInstrumente provides the C-842 four-channel precision DC motor controller witha LabVIEW development package. The C-842 motor controller has an onboardtrajectory profile generator, which can generate smooth s-curve position profiles.48