Mechanical properties of bulk Sylgard 184 and its extension with silicone oil

Abstract

Due to its simple curing and very good mechanical properties, Sylgard 184 belongs to the most widely and frequently used silicones in many industrial applications such as microfluidics and microengineering. On top of that its mechanical properties are further controllable through the curing temperature, which may vary from ambient temperature up to 200 °C; the lower the curing temperature the lower the mechanical properties (Johnston et al. in J Micromech Microeng 24:7, 2014. 10.1088/0960-1317/24/3/035017). However, certain specialised application may require even a softer binder than the low curing temperature allows for. In this study we show that this softening can be achieved with the addition of silicone oil into the Sylgard 184 system. To this end a series of Sylgard 184 samples with varying silicone oil concentrations were prepared and tested (tensile test, rotational rheometer) in order to determine how curing temperature and silicone oil content affect mechanical properties. Curing reaction of the polymer system was found to observe 2nd order kinetics in all cases, regardless the oil concentration used. The results suggest that within the tested concentration range the silicone oil addition can be used to soften commercial silicone Sylgard 184.

Dielectric Elastomer Fiber Actuators with Aqueous Electrode

“…In the tensile test, as described in Supplementary Materials and shown in Figure S1, the Young's modulus of the silicone mixture after curing was 1.26 MPa. This value is reasonable as Ecoflex 00-30 and Sylgard 184 have moduli of 0.1 MPa and 1.75 MPa (at a curing temperature 40 °C), respectively [33,36]. The elongation at break of the silicone mixture after curing was ~220%, intermediate to those of Ecoflex 00-30 (835% [33]) and Sylgard 184 (85% [36]).…”

“…This value is reasonable as Ecoflex 00-30 and Sylgard 184 have moduli of 0.1 MPa and 1.75 MPa (at a curing temperature 40 °C), respectively [33,36]. The elongation at break of the silicone mixture after curing was ~220%, intermediate to those of Ecoflex 00-30 (835% [33]) and Sylgard 184 (85% [36]).…”

Elastic Tactile Sensor Skin on Double-Curved Surfaces for Robots and Wearables

“…The resulting conductive silicone film has a volume resistivity of 0.025 Ωm and can be stretched by over 550 % without damage. It is an order of magnitude more conductive and about five times more stretchable than our first conductive silicone formulation, roughly two orders of magnitude more conductive and significantly more stretchable than the conductive TPU, more stretchable than related work using graphene [33] and carbon nanotubes [32], and even compared to many regular non-conductive silicones, it is equally or more stretchable [35] [41].…”

“…The paste is pressed into a sheet between two pieces of PTFE foil and then cured for two hours at 120 • C. The material has a maximum elongation of about 100% and a volume resistivity of 0.3 Ωm. The elasticity is already better than that of a standard non-conductive silicone that is often used for academic work [41] and the conductivity is almost an order of magnitude better than that of the conductive TPU used above.…”

Extremely Soft, Stretchable, and Self-Adhesive Silicone Conductive Elastomer Composites Enabled by a Molecular Lubricating Effect

“…Silicone elastomers are one of the most widely used materials as elastic conductors because of their excellent stability, biocompatibility, transparency, and stretchability. , In addition, the partial ionic nature of the (Si–O) bond and flexible characteristics of siloxane molecular chains can endow silicone elastomers with additional versatility through modification and design of the cross-linked network. − For example, Bao et al introduced iron chelating bonds into the molecular chain of aminomethylsiloxane and synthesized a soft and highly stretchable (up to 10000% strain) elastomer. Skov et al built up a “bottlebrush” cross-linked network structure to generate a super soft and highly elastic silicone elastomer.…”