Piezoelectric Motors, Elliptec™ Technology: OEM and Manufacturing Capabilities

Robert Capehorn
OEM Project Manager,
Elliptec Systems

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Elliptec™ Piezoelectric Motor Technology for Your OEM Application

Thorlabs’ multidisciplinary OEM applications engineering team is ready to design and build a custom Elliptec piezoelectric motor solution for your application. The highly dynamic and high-precision Elliptec motors are favored for their simplicity of assembly and operation, as well as their compact dimensions, light weight, and low power consumption (see the Technical Data tab). Our Multi-Position Sliders showcase the smooth linear movement enabled by these piezo resonant motors and demonstrate they are ideally suited for integration into a wide variety of end-applications, including those requiring the actuation of shutters and lids, the adjustment of beam-deflection mirror alignment, the toggling of locks, or the selective engagement of filters. In addition, Thorlabs’ automated manufacturing facility in Dortmund, Germany enables the high-volume production of motors capable of meeting your needs.

By working closely with you, each integration is tailored to meet the specific complexity, dimensional, and pricing requirements of the application. Thorlabs’ team is experienced in implementing a range of design solutions, from the most basic mechanical sub-assembly to fully self-contained electromechanical assemblies with integrated drive electronics. In addition to performing custom design and manufacturing services, Thorlabs can complete final assembly and functionally test every OEM unit before shipping. The image at right shows the installation of one of Elliptec's motors, being held by its wire leads, into a fixture.

Thorlabs takes pride in meeting the unique needs of your OEM application. Each project begins with a dedicated account manager establishing a strong collaborative relationship between your team and the technical resources at Thorlabs. Discussions with you are held to establish detailed design specifications, define performance goals, and identify system requirements. Thorlabs uses this information to propose the most appropriate custom design and associated manufacturing solution.

Custom Product PCBs Before
Motor Integration

Finished designs, based on modelling results, describe the manufacturing process and specify the constituent materials. Three-dimensional mechanical modeling for the project is performed using computer-aided design (CAD) software, and mechanical stress analysis is conducted using the software’s associated finite element analysis (FEA) tools. Based on the requirements of your application, electronics schematics are generated and board layouts are designed, such as the boards shown in the image at left. Thorlabs has the ability to model the mechanical components and the electronics together, which produces truly integrated designs. Materials and associated manufacturing techniques are carefully chosen to suit the application, as these have a direct influence on the operation and cost of the assembly. Candidate materials for component fabrication include both metals and plastics, and Thorlabs routinely designs for a wide variety of manufacturing techniques including machining, molding, and casting. The Implementations tab highlights these capabilities by including summaries of and links to products based on the Elliptec motor.

Please contact us today to discuss integrating the exceptional Elliptec motion control motor technology into your application.

Introduction to the Elliptec Motor

At the core of the Elliptec piezoelectric resonant motor is the piezo element, which is press-fit into an aluminum motor frame. The frame is more than just a physical housing; it is also a resonator and a transducer, and it has been designed specifically to interface with the piezoelectric element (see The Elliptec™ Motor tab for additional details). The image at lower-right shows the step in the automated machining process that mills the tip of the frame. During operation of the motor, the oscillations of the driven piezoelectric element are amplified by the frame and converted to an elliptical motion at the frame's tip. An attached spring presses the machined tip of the frame into firm contact with the driven element, which may be a rotor or other component. Power is supplied to the piezoelectric element through wires soldered to its upper and lower surfaces. The motor's direction of motion is changed and its speed is tuned by adjusting the ultrasonic frequency of the applied signal. The orientations of the spring and wire leads are chosen to suit the application, as are the lengths of the wire leads and whether or not they are terminated.

Click to Enlarge
Installation of the Elliptec Motor into a Test Fixture

Click to Enlarge
Soldering Leads to the Piezoelectric Element of the Elliptec Motor

General Specifications for the Unloaded Elliptec™ Motor, Open-Loop Configuration

The specifications listed here describe the typical characteristics of the Elliptec piezoelectric resonant motor, when it is operated under open-loop and unloaded conditions. The motor is shown being held, by the wire leads soldered to its piezoelectric element, in the image at right. The majority of applications employing the motor will incorporate it into an application and operate it under loaded conditions. When this is the case, the performance of the motor is highly dependent on the design characteristics of the system. For example, implementing the loaded motor in a closed-loop system can achieve a positional resolution of 0.5 µm, while the step size of the unloaded motor running under open-loop conditions is 10 µm. Please see the Overview and Implementations tabs for discussion of the performance that can be achieved when the motor is operated under loaded and closed-loop conditions. The piezoelectric resonant motors integrated into all designs share dimensional, weight, and frequency response characteristics.

Products Based on the Elliptec™ Motor

Thorlabs is developing a line of open-frame products based on the Elliptec piezoelectric resonant motor, which are ideal for both incorporation into OEM applications and laboratory use. As these products are released, they will be listed in the table at right and highlighted in the descriptions below. Click on a link in the table to be taken to the respective product's page. All of these products are complete packages that include the interface board, cables, and power supply (when required for operation). Other characteristics common to all include:

• Being Ideally Suited for OEMs and Applications Requiring Rapid Switching
• Micro-B USB and Picoflex^® Connectors for Control Signals
• Support of Multi-Drop Serial Communication Protocol

Control the movement of any of these devices by pressing buttons on the interface board, through computer control via the Elliptec software package that is available for download, or by sending simple signals to digital lines on the device PCB. All of these methods can be used to simultaneously control mixed networks of up to 16 individual devices.

Click to see the Separate Components of the ELL9K Bundle
Assembled Components of the ELL9K Bundle

Sliders for Switching Among SM1-Mounted Optics

• Mount up to Four SM1-Threaded Optics
• Photo-Interrupter Optical Sensor Technology for Precise Positioning
• Compatible with 30 mm Cage System Components

Thorlabs' ELL6K Dual-Position and ELL9K Four-Position Slider packages are designed to exchange mounted optics for one another in an optical path. The ELL6K mounts two SM1-threaded optics and the ELL9K mounts four. Both sliders are lightweight and compact, with the four-position slider weighing 70.0 g and having dimensions of 141.0 mm x 77.7 mm x 14.2 mm when the carriage is in one of the end positions. The ELL6 features one Elliptec motor, while the ELL9 has two of these highly dynamic motors. As they have no gearing, the motors can stop within microseconds. This allows the motors to respond quickly to signals from the photoelectric sensor and accurately position the slider. In addition, the motors include no magnets, which makes them compatible with EM-sensitive environments. The contents of the ELL9K bundle are pictured at the right, and components included with the ELL6K and ELL9K and listed in the table at the right.

The movement of the slider may be controlled by pressing buttons on the remote handset, through computer control via the Elliptec software package that is available for download, or by sending simple signals to digital lines on the slider board. The ELL6K dual-position and ELL9K four-position sliders are well suited as a filter changers, and the ELL6K is also used as a shutter. The sliders possess SM1-threaded (1.035"-40) bores, with 3.5 mm deep threads, at each position. Four 4-40 tapped holes on the PCB allow the sliders to be mounted with and integrated into optical setups using Thorlabs' 30 mm Cage System.