I am looking for a material that has stress-strain relationships similar to human tissue (see attached figure). The tissue has a very low small strain Young's modulus (around 10kPa), but increases quickly with strain.
We've had some success matching the low-strain Young's modulus using a soft silicone with silicone thinner. However, this material does not possess the nonlinearity of human tissue.
Does anyone have any suggestions for a material (or additive) that could be used in this application?