Piezo Walk Drive
The Advantages of a Piezo Walk Drive
To meet the semiconductor industry need of position resolution, reliability, and long term stability, Piezo Walk® Drives started development more than a decade ago. Today the drives have developed further and several variants are available for other application areas.
- Nanometer Precision with a High Feed Force
- Scalable travel range due to scalable runner length
- Resolution to 0.03 nm
- Self-locking when at rest, no heat generation
- Nonmagnetic and vacuum-compatible operating principle
- Three technologies to serve a broad spectrum of applications
- Integration levels from an OEM motor to a multi-axis positioning system
Field of Application
Our piezomotors are in principle vacuum-compatible and suitable for operation under strong magnetic fields. Piezo walking drives can also be used in clean rooms or in environments with a hard ultraviolet radiation
Constant Velocity and Smooth Driving
Constant velocity and smooth driving are best achieved in nanostepping mode, but the maximum attainable velocity is higher in full-step mode as a result of the 1 nm open-loop motion.
Smooth Incremental Motion with Long Endurance
The drive achieves an exceptional stable stepsize after a run-in phase of 10-15 km. The constant step size is a measure for the high load capacity and endurance of the drive.
Lifetime and reliability
The motion of the piezoceramic actuator is based on crystalline effects and is not subject to any wear. Unlike other piezomotor principles, the coupling of the piezo actuators to the runner is not subject to sliding friction effects; the feed is achieved by the physical clamping and lifting of the actuators
Our Piezo Walk drives have proven in a standard test environment under normal atmospheric conditions to have endurance over 100 km of continuous running under load.
Direct Drive Principle
Piezo walking drives do not need additional mechanical coupling elements. The piezo drive acts directly on the runner and no other moving parts limit the precision and reliability. That is an advantage compared to motor-spindle systems where connectors and gearheads are used.
Preloading the piezoelectric actuators against the runner ensures that the drive self-locks when at rest and powered down. As a result, it does not consume any power, does not heat up, and keeps the position mechanically stable. Applications with a low duty cycle that require a high time and temperature stability profit from these characteristics
Open-loop 1 nm Motion
Piezo Walk® Drive Technology
Maximum speed and holding force
The NEXTLINE combines piezo clamping and shear actuators in order to move a rod. With feed forces of several 100 N, the drive feature high force and stiffness. Moreover, they are capable of dynamically compensating oscillations in the range of a few micrometers with nanometer resolution. Lastly, the NEXTLINE® is designed for higher positioning and holding forces of up to 800 N, and will also work at lower velocities.
For compact solutions
Precision walking drives convert the walking motion by means of piezo bending elements. These drives are more compact and achieve higher velocities, developing forces in the range from 10 to 20 N. A suitable selection of the piezo elements optimizes step size, clamping force, velocity, and stiffness for the respective applications.
Combining dynamics & force generation with long lifetime
PICMAWalk drives achieve feed forces up to 50 N and holding forces to 60 N. The maximum velocity is 15 mm/s. PICMAWalk uses the proven PICMA® multilayer piezo actuators with lower piezo voltages of 120 V. PICMA® piezo actuators also ensure a long lifetime and the outstanding reliability of the PICMAWalk technology.
As essential components, a Piezo Walk Drive has several piezo actuators that are preloaded against a guided runner.
These piezo actuators perform a walking motion during operation that causes a forward feed of the runner. The piezo actuators can be operated to perform very small walking and feed motion so that a high motion resolution of far below one nanometer is achieved.