Berlin 2012 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 27: Poster: (Hydrogels) and Elastomers

CPP 27.16: Poster

Mittwoch, 28. März 2012, 11:00–13:00, Poster A

Phase-transition actuator — •Roland Altmueller, Reinhard Schwoediauer, Siegfried Bauer, and Ingrid Graz — Soft Matter Physics, Institute for Experimental Physics, J. Kepler University, Altenbergerstrasse 69, 4040 Linz, Austria

Dielectric elastomers have widespread applications in sensing, for energy harvesting and actuation. By applying a sufficiently large voltage the elastomer in between two compliant electrodes deforms and complex shapes such as grippers or walkers are realized. However, the required driving voltages are large, often in the kilovolt range, so the reduction of the driving voltage has been identified as a key challenge in the field.

Here we present phase-transition actuators where an elastomeric frame undergoes large deformations caused by the phase transition of an embedded liquid from the liquid to the gaseous state. The phase transition in the liquid is simply induced by electrical Joule heating. A very large deformation is feasible on the base of the huge volume changes upon the liquid gaseous phase transition. Low voltage operation is guaranteed, since the deformation relies on liquid heating, albeit with larger power consumption in comparison to DEAs.

Biaxial deformations of up to 120 % are achieved in a 9 mm wide liquid reservoir within a PDMS elastomer at a driving voltage of 10 V and an input power of 1 W, with a large blocking force of 5-6 N. The proposed actuator concept is easily prone to miniaturization, potentially useful in Braille readers.