High-strain dielectric elastomer for actuation

This paper presents preliminary results on the characterisation of the actuating performances, never explored before, of an elastomeric material (Dr Scholl's, Canada, Gelactiv tubing), to realise dielectric elastomer actuators. Strain and stress performances of this material were compared to those of the most currently used acrylic elastomer (3M, U.S.A., VHB 4910). Planar actuators were realised and tested, using films of the two materials, coated with compliant electrodes made of carbon grease. Following the application of a two-second high-voltage impulse, the isotonic transverse displacement and the isometric transverse force were separately measured along a prestrained direction. Actuators made of the new elastomer showed, respect to those made of the acrylic polymer, a lower dielectric strength, a transverse strain more than twice greater for the same applied electric field (e.g. 1.8 % against 0.7 % @ 27 V/μm) and a transverse stress less than twice smaller (e.g. 3.7 KPa against 5.3 KPa @ 24 V/μm).