Long range micropositioning
How it works
Long-range micropositioning relies on motors, so the actuator is activated several times and its successive displacements are added-up mechanically to generate a large motion. The motorised stage can be driven by various types of motors: stick slip, standing wave, “legged” etc.
The most common motor is the so-called stick-slip motor. Here, the piezoelectric actuator is placed in frictional contact with a movable table. When a slowly increasing voltage is applied to the piezo actuator, it expands, thus moving the table (stick). Then the voltage is decreased rapidly, so that the piezo contracts. Due to the inertia of the table and the high acceleration of the actuator, the contact slides (slip), resulting in almost no displacement of the table. When the procedure is repeated, the table can be moved over large distances.
Figure showing the basic functionality of the actuator driving the stick-slip motor
In addition, it is possible to adjust the voltage on the actuator to “fine-adjust” position within a “step”, achieving nanometer resolution.
Which piezo elements can be used for motorised stages?
The design of the piezo element varies greatly depending on the motor technology employed. For direct-acting stick-slip motors, step size in the few microns range is common. This can be achieved using a single multilayer actuator such as our NAC2012 (free stroke 3 µm).
Depending on the motor technology, other systems can use multilayer stacks, multilayer components with a complex geometry or monolayer components. Do not hesitate to contact us with your custom design.
