U-521 PILine® Linear Positioning Stage

Compact stage with ultrasonic piezomotor

PI U-521
Positions small loads quickly and with precision: Velocity to 200 mm/s, minimum incremental motion to 0.3 µm
Space-saving: Only 35 mm in width and 15 mm in height
Self-locking when switched off: Saves energy and reduces generation of heat
Custom designs available on request

Precision-class linear positioning stage

PILine® stages are particularly suitable for applications that require fast precision positioning. When switched off, the self-locking drive holds the position of the stage mechanically stable. Energy consumption and heat generation are therefore considerably reduced. Applications with a low duty cycle that are battery-powered or heat-sensitive benefit from these characteristics. The position of the axis is measured by an encoder and an optical reference switch allows reliable repeatable motion. The piezomotor drive principle and its electrical operation is inexpensive and can be customized.

PILine® ultrasonic piezomotor

An integral part of a PILine® ultrasonic piezomotor is a piezo actuator that is preloaded against a movable, guided runner via a coupling element. The piezoceramic actuator is excited to ultrasonic oscillation by a high-frequency AC voltage between 100 and 200 kHz. Deformation of the actuator leads to periodic diagonal motion of the coupling element relative to the runner. The feed created is a few nanometers per cycle; the high frequencies lead to the high velocities. Preloading the piezoceramic actuator against the runner ensures self-locking of the drive when at rest and switched off.

Direct position measurement with incremental encoder

Noncontact optical encoders measure the actual position directly at the motion platform with the greatest accuracy so that nonlinearity, mechanical play or elastic deformation have no influence on position measuring.

Valid patents

US patent no. 6,765,335B2

European patent no. 1267425B1

Fields of application

Micromanipulation, automation, biotechnology, sample manipulation, sample positioning, applications with limited space, vacuum applications to 10-6 hPa (optional).


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Drawings / Images

PI U-521 Drawing




PI Datasheet U-521

Compact Linear Stage Fast PILine® Direct Drive, Incremental Encoder
2016-04-08 R2
pdf - 10 MB
pdf - 10 MB



Short Instructions MP121EK

M-66x, M-68x, U-521, U-62x, U-651 PILine® Stages
pdf - 497 KB

User Manual MP138E100

U521 Linear Positioning Stage
pdf - 864 KB
pdf - 893 KB

3D Models


U-521 STEP

zip - 1 MB