The motion system employed to move the four objectives is of great importance for the structure of the microscope. For this purpose, a highly compact PIHera P-622.1 precision positioning system with 300 µm travel (alternatively 900 µm) per objective is used, each controlled by a E-709.CHG controller.
The P-622.1CD PIHera precision positioner is based on all-ceramic PICMA® piezo actuators whose movement is transmitted by zero-play flexure guides. The travel range (closed-loop) is 250 µm with a repeatability of ± 1 nanometer! The movement is measured directly at the motion platform without any influence from the drive or guide elements.
Capacitive sensors determine the distance to the sample chamber with subnanometer resolution without contacting. They guarantee excellent linearity of motion, long-term stability, and a bandwidth in the kHz range.