This is not my field, but as far as I could read, dielectric elastomers and electro-adhesive devices share similar properties in both dielectric constant and electrical breakdown values.

However, when searching for electro-adhesive devices, these can achieve around 1 newton force per centimeter square of surface area. While dielectric elastomer actuators can achieve actuation forces of 1000 times its own weigth, which would be around 10 times stronger than electro-adhesive materials.

On top of that, the materials used on each one are different (as far as I could read the articles).

Why is that?