With the N-216 series NEXLINE drives, Physik Instrumente (PI) from Karlsruhe has now available in its product range new highload linear actuators which combine travel ranges of 20 mm, pull or push forces of up to 600 N and positioning accuracies in the nanometer range.They are suitable for openloop and closedloop operation: The integrated encoder of the versions which can be operated in closedloop mode has a resolution of 5 nm over the total travel range. In openloop mode, e.g. for highly dynamic applications, position resolutions of up to 30 picometers are achieved. In order to make the best possible adjustment of the drives to the relevant application, two different controllers are available: The E-755 offers all functions for a positioning with nanometer accuracy and covers thus most applications well. The E-712 controller system additionally has improved linearization algorithms for extremely steady motion and allows faster feedforward motions with maximum force.
The NEXLINE drives produce the feed forward using a combination of longitudinal and shearing piezos, i.e. piezo actuators with different motion characteristics. If they are driven appropriately, clamping as well as also driving motions can be realized, which resemble the motion of a quadruped. The load can thus be moved with constant speed over the total distance. Additionally, in this way the position can be actively readjusted after the target position is reached. This can be used to compensate vibrations. Since the drives have no moving parts such as gears or leadscrews, there is no mechanical play and no wear.