WORKING PRINCIPLE

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The great success of attocube systems positioners is based on the unique combination of a patented driving technology, the powerful design, the selection
of high-quality materials, and the long experience of the attocube systems staff. The product line of linear, rotary, and goniometer-like positioners and scanners offers you a chance to discover new experimental possibilities. The patented driving technology plays an important role in achieving such a bandwidth of applications. Depending on your requirements you can choose from different sizes, travel ranges, and direction of movement. Our positioners allow you to move reliably objects over centimeter range with atomic precision under a large variety of conditions such as low temperature, high magnetic fields or ultra high vacuum. Optional many of the positioners can be equipped with a position sensor for closed loop operation with nm-resolution. By assembling several stages you can obtain positioning units with up to six degrees of freedom.

Travel Mechanism

attocube translation stages are powered using slip-stick motion. The basic principle of translation stages based on slip-stick inertial motion is the controllable use of the intertia of a sliding block. In our slip-stick inertial translation stages, the sliding block slips along a guided rod to which it is otherwise clamped (sticking) in frictional engagement. To obtain a net step, the guiding rod is first accelerated very rapidly over a short period of time (typically microseconds) so that the intertia of the sliding block overcomes the friction. This way, the sliding block disengages from the accelerated rod and remains nearly nondisplaced. Subsequently the guiding rod moves back to its initial position slowly enough so that the sliding block this time sticks to it and thus makes a net step. Periodic repetition of this sequence leads to a step-by-step motion of the sliding block in one direction. A piezo electric ceramics pushes or pulls the guiding rod and the exact sequence in the slip and stick motion is controlled by an appropriate voltage signal.

The main challenge of using slip-stick translation stages for imaging is to obtain a reliable and controllable motion of the sliding block over millimeter ranges and with small and reproduceable enough steps. The main techical challenge is to control the frictional engagement. The design of our rod and sliding block is such that all surfaces in frictional contact are planar, producing this way a homogeneous and constant frictional force engagement. A major benefit of this technique is that large centimeter motion ranges can be obtained even at cryogenic temperatures, where PZT piezo ceramics are usually limited to scanning ranges of only a few µm.
Main Advantages

This driving mechanism has several advantages:

> When a position is reached after a series of steps, zero voltage applied to the piezo. Therefore, there is no noise and no drift caused by any external electronics.

> Only low to moderate voltages are needed to drive the positioners. In attocube systems positioners, piezos with maximum 60V or 150V are used. As a consequence, shielding for high voltages is not necessary, and cabling and connectors rated for low voltages can be used.

> As the piezos in the positioners can also be used for quasi-DC scanning , the device functions as a coarse stepper and a fine scanner at the same time. This is a tremendous advantage in terms of compactness and stability of the setup.