Customized Human Skin Simulants

A simulant which precisely mimics the linear and non-linear mechanical properties of “the human skin” would be indispensable for assessment of load responses (and discomfort) produced by wearable technologies in the aerospace industry, be it an electronic sensor or a full body suit. In the current work, for the first time, a methodology has been developed to fabricate customized human skin simulants for any person and part of the body. The material comprises of four parts of silicone, which when mixed in different ratios, produces skin simulants with different stiffness properties. Extensive mechanical tests have been performed on different variants of the human skin simulants, and their stress versus strain responses have been matched with actual human skin test data from the literature. Also, the fracture properties of the simulants have been found to be in close range of the actual human skin. Additionally, non-linear hyperelastic constitutive models were used to fully characterize the mechanical behavior of the skin simulant variants. Mechanical tests on freshly excised porcine skin were conducted to validate our test results. To date, such accurate skin simulants has not been developed anywhere to the best of our knowledge. The material is cheap ($15/lb), has no biosafety or handling issues (unlike cadavers, cowhides or porcine skin), and castable to any shape or size. Besides testing, the skin simulants could also be used to develop liners for the wearable technologies, which are just like the skin of the person wearing it, thus reducing discomfort due to material mismatch and friction. Additionally, the skin simulants find applications in the area of manufacturing of prosthetics (liners) and orthotics, military grade armors and personal protection equipment (PPE), and testing of non-lethal and less-lethal ballistics.