Piezo motors are linear or rotary motors offering high precision and blocking at rest. These properties make them suitable for long stroke micro positioning applications.

CEDRAT TECHNOLOGIES has experimented different kinds of piezoelectric motors either by retrofitting / testing standard piezomotors or by developing new original concepts, in the context of space applications or fine instrumentation projects:

• Inchworm piezo motor : These motors are based on the quasi-static steps of the piezo stator which drives a second member. They offer a good controllability but are slow (<10mm/s) and expensive as multi-phases. CEDRAT TECHNOLOGIES has experimented such motors with some first versions of its LPM Linear Piezo Motor (in a CNES French space agency project) or with the RPMHPP Rotating Piezo Motor (in ESA Eu Space Agency project).

• Ultrasonic motor (USM) : These motors are based on an ultrasonic vibration (generally elliptic and using resonance) of the stator which drives a second member (as a rotor). They are fast (> 100mm/s), offer a medium controllability and are sensitive to variations of loads and environment. Their electronics can be complex to track resonance. The LPM20-3 space qualified Linear Piezo Motor from CEDRAT TECHNOLOGIES is a multi-mode ultrasonic motor (MMUM). It is vacuum compatible and space qualified thanks to CNES and EADS projects. Rotating piezo electric motors, such as the RPA for ESA, and rotating magnetostrictive motors have also been developed by CEDRAT TECHNOLOGIES using this concept to offer a large torque at low speed. CEDRAT TECHNOLOGIES has also retrofitted Travelling Wave Ultrasonic Motors (TWUM) from Shinsei to make them space compatible.

• Inertial Stepping Motor (ISM) : These motors also called (Smooth) Impact Drive Mechanisms (IDM or SIDM) are based on the transient steps of the piezo stator which drives a second member. They offer medium speeds (10-50mm/s). These motors need only one piezo ceramic and one electronic channel, leading to a good miniaturization potential. CEDRAT TECHNOLOGIES has developed the SPA Stepping Piezo Actuator, a new piezo motor based on the ISM concept and benefiting from the APA® heritage.

The following examples show various prototypes and customised products. To learn more about our piezo motors see our related publications on rotating piezo motors or on linear piezo motors. A developer kit based on the SPA30uXS is also available.