How to Align Opto-Mechanical Components with Simple and Effective Tools

Stepper motor driven precision actuators have a good track record for precision alignment applications. They provide high resolution, force, and relatively high speed. Their downside is size and heat generation (especially when used in high-resolution micro-step mode, the motor will not hold a position when powered off). 

Piezo-ratchet-motor-driven actuators can be designed much smaller than conventional stepper motor actuators. They provide nanometer resolution, very low energy consumption (heat dissipation), and are self-locking when powered down. Due to the compact size / form factor, they can be easily used to replace manual micrometers. For applications where the absolute position is not relevant (feedback is provided by a system parameter such as optical power, focus, etc), open-loop actuators can be used.  This situation also allows for simple control solutions, where one driver can be used to operate multiple actuators in sequence, by an internal electronic switch. Compared to traditional motorized precision-actuators, piezo-ratchet motor actuators provide lower velocity and are ideal for “set-and-forget” applications that would typically be handled by manuals micrometers.

Piezo ratchet motors are “stick-slip” type motors that make use of inertia (table cloth trick). Inertial drives utilize the cyclical alternation of static and sliding friction which is generated by a piezo element that expands slowly and contracts quickly, in the case of the PiezoMike motors, turning a fine-pitch screw. Each step is as small as 20 nanometers.

PiezoMike Piezo ratchet motor actuators are available for ambient and vacuum environments. In addition to actuators, solutions with kinematic mirror-mounts (tip/tilt mounts) are readily available for integration.