Towards the material limit and field concentration smoothing in multilayer dielectric elastomer actuators

Abstract

Performance of dielectric elastomer actuators is closely related to its breakdown field. On the other hand, to enhance the available energy, multilayer configuration is needed to increase the amount of active material. However, multilayer configuration suffers from a drastic reduction of the affordable electric field related to field concentration at edges. After showing how the conductivity of the air helps to smooth the field in a single layer configuration, this effect has been mimicked in the multilayer by adding carbon particles in a thin silicone layer around the electrode. A change in the electric properties around the edges reduces the local concentration of the electric field and allows a significant improvement of the voltage breakdown in the multilayer structure. Therefore, the performance of multilayer has been considerably enhanced.

A novel soft cardiac assist device based on a dielectric elastomer augmented aorta: An in vivo study

“…Compliant electrodes made of carbon‐doped silicone (Figure 1c, black layers) were screen‐printed on the elastomer sides with a silver ink line crossing the electrode to allow for electrical connection in the end. All the sheets were then glued together with a silicone glue lightly doped in carbon (Figure 1c, gray layers) 17 . The stack was then rolled twice and glued together with liquid silicone around a 20 mm diameter poly(methyl methacrylate) (PMMA) cylinder and cut at the desired dimensions.…”

Feasibility of a Dielectric Elastomer Augmented Aorta

“…Electrical based estimation (350 mJ charge ‐ 126 mJ discharge = 224 mJ transferred) is not accurate because the DEA has losses both from the mechanical part and from the electrical part. [ 16 ] A direct approach consists of estimating the mechanical work done by the DEAA. For this purpose, a pressure probe (0.36 mm diameter) measures the static pressure inside the DEAA (on the axis) thanks to a lateral opening on the side of the tip (Figure 7A).…”

“…First a carbon‐based electrode is deposited on top of a silicone film (Elastosil film 2030 200 µm) with its support to make a module (① in Figure 2 and in Figure B. In panels ② and ③, thanks to a silicone based adhesion layer, [ 16 ] the silicone film and its electrode are successively transferred up‐side down from their initial support to the stack (the first layer being on a polyethylene terephthalate [PET] substrate). The silicone‐based adhesion layer [ 16 ] made of carbon black powder and silicone also smooths the field concentration and improves the withstand voltage.…”

“…In panels ② and ③, thanks to a silicone based adhesion layer, [ 16 ] the silicone film and its electrode are successively transferred up‐side down from their initial support to the stack (the first layer being on a polyethylene terephthalate [PET] substrate). The silicone‐based adhesion layer [ 16 ] made of carbon black powder and silicone also smooths the field concentration and improves the withstand voltage. After the deposition of the last electrode, the stack (Figure 3C) is then cut (④ in Figure 2).…”

“…Fabrication of the Multi-Layer DEA: The manufacturing of the multilayer structure consisted of stacking two modules on top of each other. First, a silicone adhesion layer, [16] was deposited with the film applicator coater on a PET substrate (Mylar Typ. A, 125 µm, DuPont Teijin Films, USA) at 20 mm s −1 with a profile rod 4.57 um (Zehntner ZSA 2110 Wirebar applicator, Proceq Group, Switzerland).…”