Advantages of piezo technology

The size of piezo motors typically lies in the order of magnitude of millimeters or centimeters. The small-sized motors enable the miniaturization of all kinds of automated systems.

Due to the high frequency electric drive signals, the human ear is unsensitive for ultrasonic piezo motors. This feature makes ultrasonic piezo stages particularly suitable for noise-sensitive applications and for protecting the health and well-being of human operators.

Piezo stages are well-known to easily achieve micrometer precision. For high-tech applications, even sub-nanometer precision can be attained.

Due to the high frequency driving principle, high maximum positioning speeds can be attained of over 100 millimeter per second.

Unlike electromotors, piezo motors do not produce any significant magnetic fields. By carefully selecting the materials of the stage, piezo stages can be used in strong magnetic fields (several Tesla) or applications where no magnetic disturbance or interference is allowed.

Most piezo stages are used for point to point positioning, but ultrasonic piezo motors can be programmed to follow low and constant speed motions of several micrometer per second. Depending on the speed, deviations smaller than 1% can be achieved, unlike the typical stepping or saw-tooth (stick-slip) motion patterns.

Since there is no convection in vacuum, electromotors can rapidly heat up and degrade when placed in vacuum. Piezo motors on the contrary consume less energy and are very compact, which makes them suitable for in-situ vacuum motion.

All piezo motors are susceptible to wear because of the frictional operating principle. Stick-slip and inertial piezo motors typically show a limited lifetime in the order of 1 to 10 kilometer, while piezo stepping motors are even more prone to wear. Ultrasonic piezo motors on the contrary have the advantage of achieving lifetimes of 100 kilometer and more.

As opposed to piezo actuators, piezo motors can achieve macroscopic movement. The travel range is only limited by the length of bearings or rails used.

Xeryon’s ultrasonic piezo motor shows a very low power consumption, smaller than 1 Watt. These motors are always operated on natural eigenfrequencies and at these frequencies, the amplitude of motion is maximized for the applied electrical power. This is one of the reasons why these motors are used in portable, battery powered, devices.

Piezo motors benefit from a self-locking property. Even when the motor is powered off, the stage remains stationary. This is because the operating principle is based on friction.

Through the use of advanced control algorithms, it is possible to make individual positioning steps of nanometer level. Because of the static holding force it becomes possible to keep this extreme positioning resolution with zero drift.

Piezo motors work on a frictional mechanism. There is no need for a transmission, such as belts or gears. This reduces the complexity of the system and results into a backlash-free and more precise positioning.

Xeryon’s ultrasonic piezo motors are driven by low voltage signals, which are always smaller than 48 Volt peak to peak. For hand-held devices, the motor can be powered via a standard 5 V USB input voltage.

The position of ultrasonic piezo stages can be overridden manually, by overcoming the static friction force. This can be useful for coarse alignment and such an action will not influence the lifetime of the stage.