Design of reliable silicone elastomers for dielectric elastomers and stretchable electronics

Silicone elastomers are widely used due to the favourable properties, such as flexibility, durable dielectric insulation, barrier properties against environmental contaminants and stress-absorbing properties over a wide range of temperatures ≈ -100 °C to 250 °C. Additionally they are mechanically reliable over millions of deformation cycles, which makes them ideal candidates for dielectric elastomers and stretchable electronics. In research on dielectric elastomers and other emerging technologies, the most common silicone elastomer utilized is Sylgard 184. One of the main advantages of this formulation is the low viscosity which allows for easy processing resulting in almost defect-free samples. Furthermore, its curing is robust and not as sensitive to poisoning as other silicone elastomer formulations. Commonly, the shortcomings of the final properties of Sylgard 184 are overcome by mixing the base polymer and the curing agent in non‐stoichiometric ratios and also by blending it with softer types of commercially available elastomers. Researchers rarely formulate their own tailor‐made silicone elastomers, probably due to the scarcity of information in literature on how to do this. This report aims to equip the beginners in silicone research with knowledge on how to prepare silicone elastomers with specific properties without compromising the mechanical integrity of the elastomer and thereby avoiding mechanical failure. Here the main focus is put on designing and formulating soft, reliable, and reproducible elastomers.