Positioning systems and linear actuators which operate on the basis of piezo ceramics are particularly suitable for use in high and ultrahigh vacuum at pressures down to 10-10 hPa (mbar), because the motion is based on displacements in the crystal structure. Therefore no conventional mechanical elements such as shafts or gears are necessary and thus no maintenance or lubrication either. Neither is there a danger of an outgassing of the materials used. The PICMA ® actuators used by Physik Instrumente (PI) from Karlsruhe are manufactured by its subsidiary PI Ceramic. They are completely encapsulated in ceramic and do not use a polymer insulation. The German Aerospace Center (DLR) could not detect any measurable outgassing rates during appropriate testing. The ceramic insulation additionally increases the usable upper limit of the temperature range to 150 °C; an advantage for baking out in vacuum applications.
Piezo stepping drives from the NEXACT® or NEXLINE® range - also manufactured completely in ceramic and vacuum compatible - lend themselves for larger travel ranges. Depending on the version, positioning systems equipped with piezo stepping drives are suitable for travel ranges up to 30 or up to 125 mm and more. The positioning systems can cope with considerable loads. Heavy load versions achieve drive forces of up to 600 N, versions optimized for speed drive with speeds of up to 10 mm/s at a drive force of 10 N.
Other characteristics of piezomotors can also be advantageous: They do not need electric power once the position is reached. There is therefore no undesirable heat generation in the vacuum. Additional brakes are not required because piezomotors are selflocking when at rest.
Piezo stepping drives from the NEXACT® or NEXLINE® range - also manufactured completely in ceramic and vacuum compatible - lend themselves for larger travel ranges. Depending on the version, positioning systems equipped with piezo stepping drives are suitable for travel ranges up to 30 or up to 125 mm and more. The positioning systems can cope with considerable loads. Heavy load versions achieve drive forces of up to 600 N, versions optimized for speed drive with speeds of up to 10 mm/s at a drive force of 10 N.
Other characteristics of piezomotors can also be advantageous: They do not need electric power once the position is reached. There is therefore no undesirable heat generation in the vacuum. Additional brakes are not required because piezomotors are selflocking when at rest.
