03 Sep 2010

Piezo motors technologies

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

The CEDRAT Group 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 and has also experimented the Squiggle® piezo motors from Newscale which are suited to tiny locking or positioning mechanisms.

  • 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 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.

Stepping Piezo Actuators: SPA video   technological leaflet   request for information
Description: Stepping Piezo Actuators (SPAs) are new long-stroke linear piezoelectric motors for micro/nano positioning applications. The load can be fixed firmly to the shaft. Non magnetic or cryogenic versions upon request. MICRONORA 2008 Golden Micron !
Applications: Nano positioning, Locking, Refocusing, Piezo Valves, Micro Robots ...
Status: Prototype
Micro Stepping Piezo Actuators : SPA30uXS video      request for information
Description: The Stepping Piezo Actuator SPA30uXS is a new high-force density non-magnetic stepping linear micro piezomotor : Mass < 1gr ; Blocking force at rest > 0.5N ; Max actuation force > 0.2N ; Stroke > 3mm ; Speed > 50mm/s ; Resolution < 1nm
Applications: Embedded microsystems, cameras, MRI-compatible, microvalves, medical implant
Status: Prototype
Piezo Motor Upgrade    technological leaflet   request for information
Description: CEDRAT Group has upgraded commercial off the shelf – COTS rotative piezoelectric motors by changing several parts and carrying out acceptance tests. For ex TWUM motors have been made space compatible.
Applications: Aerospace, defence, non-magnetism instruments
Status: Prototype
Force Piezo Actuator: FPA    technological leaflet   request for information
Description: FPAs are new long stroke linear stepping piezo actuators for Nano positioning applications. FPA offers much higher forces than SPA, but much lower speed.
Applications: Micro/Nano positioning, Locking mechanism...
Status: Detailed design
Rotary Piezo Motor: RPMHPP    technological leaflet   request for information
Description: RPMHPP is a Quasi-static stepping Rotary Piezoelectric Motor for space telescope applications. It displays the general advantages of a piezo motor, but an extremely high angular resolution and a wide temperature range.
Applications: Aerospace, High angular Precision Positioning, telescope...
Status: Space evaluated
Rotary Piezo Actuator: RPA video   technological leaflet   request for information
Description: RPA is a Resonant Ultrasonic Rotary Piezoelectric Motor developed for space applications (robotic arm joint, instrument motorisation).
Applications: Aerospace, robot arm, High positioning accuracy...
Status: Space evaluated
Linear Piezo Motor: LPM20-3    technological leaflet   request for information
Description: LPM20-3 is an Ultrasonic Linear Piezoelectric Motor developed for space applications with CNES support. It offers high forces (20-50N) and speed (20mm/s) with very low electric power (12W).
Applications: Aerospace, Refocusing, High positioning accuracy...
Status: Space evaluated