Promising technologies presented in Bremen

Two new technologies were presented at Actuator 2012 in Bremen in June 2012 by Noliac engineers. One technology is the development of a low voltage DEAP based on piezo transformers, and the other is regarding a system which reaches its target speed within milliseconds through the use of Piezo Actuator Drive (PAD). Both technologies are very promising. 

Noliac publications

Low voltage DEAP based on piezo transformer

Development of a low voltage Dielectric Electro-Active Polymer actuator (PDF)

Abstract:

In the present paper, a low-voltage Dielectric Electro-active Polymer (DEAP) device is presented. It is based on the DEAP technology, together with a very compact driver, utilising piezoelectric transformer technology. A major limitation for the use of DEAP for actuator application is the high voltage required for operation. The device presented in this paper is only supplied by low voltage and control signals leading to volume and mass savings for the overall system as well as easier integration.

The driver is based on a piezoelectric transformer, combining high step-up ratio, high efficiency and small size. Several prototypes have been produced and tested. Test results indicate that the mechanical integration between electronics and DEAP has some impact on performance. However, performance and reliability are still very good, so this technology is promising. New prototypes are being developed with even improved performance.

Target speed within milliseconds with PAD

Improved dynamics, resolution and repeatability of a linear positioning system through the use of Piezo Actuator Drive (PAD)(PDF)

Abstract:
In the present paper, the improvements led by the switch to PAD technology for a positioning application are presented. Several prototypes have been designed, produced and tested in Noliac according to specific requirements. The design includes a reduced gear ratio, leading to benefits in terms of backlash and inertia. Furthermore, the use of PAD allows a simplification of the system, with the suppression of a position feedback sensor and the corresponding control loop. Sub-micron resolution and repeatability down to 2,5!m peak-to-peak were demonstrated, orders of magnitude better than required for that application.

The new design demonstrates very good dynamics. The system reaches its target speed within milliseconds, so start/stop times can be minimised. Furthermore, lower inertia and low friction induce a widened controllable speed. This means that the output can be controlled down to virtually zero speed, allowing a continuous adjustment of its position.

As a result, performance and usage of the positioning system can be improved, leading to quality improvements and cost savings.

 Ramp response for speeds of 2.9; 1.4 and 0.7mm/s.