Design and Control of a High-Speed Positioning System Based on Dielectric Elastomer Membrane Actuators

Abstract

Dielectric elastomers (DEs) represent a new family of electromechanical transducers capable of undergoing large actuation stroke (>100%), allowing it to achieve performance that is not attainable with standard transduction technologies (e.g., piezo). Furthermore, DEs' high flexibility permits us to design actuators with various shapes and sizes, allowing us to meet desired stroke or force specifications in a wide range of applications. This work aims to show the potential of DE technology in micropositioning applications by presenting development, manufacturing, and control of a one-directional flexure system driven by two circular out-of-plane DE actuators (COP-DEAs). The two COP-DEAs are coupled in an antagonistic configuration that, under the application of a voltage, provides push-pull forces on a custom built compliant unidirectional stage. After describing design and fabrication of the actuator, experimental characterization is performed. Finally, a feedforward control strategy is implemented in order to let the displacement follow a desired periodic profile. The unloaded stage is capable of accurately following sinusoidal and triangular trajectories, having a fundamental frequency of 60 Hz and a peak value of 40 μm, with a maximum error of 2 and 5 μm, respectively.