  In this paper, a contactless linear slider for precision positioning able to
operate in cryogenic environments is presented. The device, based on
superconducting magnetic levitation, does not present contact between the
slider (composed of a permanent magnet) and the guideline (made of
high-temperature superconducting disks) of the mechanism, thereby avoiding any
tribological problems. Moreover, the slider is self-stable and the
superconductors provide inherent guidance to the permanent magnet in the
sliding DoF due to the high translational symmetry of the magnetic field that
leads to low power consumption. A sub-micrometre resolution and a symmetric
stroke over 9 mm have been demonstrated at cryogenic temperatures. In addition,
a set of design rules for this kind of mechanism has been proposed and
experimentally validated. These rules demonstrate that the performance of the
device can be tuned just by modifying some geometrical parameters of the
mechanism. In this way, the sensitivity and stiffness, resolution, angular run
outs and power consumption can be adjusted for different applications and
requirements.
