Development of a Synthetic Skin Simulant Platform for the Investigation of Dermal Blistering Mechanics

Excessive frictional loading to the skin often results in the formation of blisters, due to the transmission of shear loading to the interfaces between dermal cell strata. The consequences of blistering range from mild discomfort to serious infection. In some patients, such as those disposed to epidermolysis bullosa or neuropathic diabetes, blisters can severely degrade life quality. Investigation of environmental and application parameters that affect blister formation has occurred primarily as a qualitative, observational pursuit on human subjects, which has often led to confounding of data and lack of repeatability. The authors have developed a Synthetic Skin Simulant Platform (3SP) that reproduces the mechanical behavior of human skin when exposed to tribological loading. The platform is an assembled construct of bonded elastomeric layers that act as surrogates for the epidermis, basement membrane, dermis, and subdermal structure. Epidermal (top layer) materials are typically silicone or polyurethane films with a friction coefficient akin to human skin, while sublayers display mechanical properties similar to their anatomical analogs. Blistering is evident optically by examining the separation voids formed after applying shear loads to the epidermal layer. The 3SP has been used in a two-axis pin-on-flat tribometer with a stainless steel indenter to study the normal load and friction coefficients encountered at the onset of frictional blistering. The 3SP allows for modulation of friction coefficient, interfacial adhesion strength, and subdermal stiffness for investigation of blistering damage to various anatomical sites. Experimental results have been compared to human test data and have shown that the 3SP provides the potential to make significant advances with respect to skin tribology research.