Willemet, L. (2022). Mechanical Model of Skin Deformation. In L. Willemet (Ed.), The Biomechanics of the Tactile Perception of Friction (pp. 43–55). Springer International Publishing. https://doi.org/10.1007/978-3-031-16053-0_3
The tactile perception of shape, softness, or slipperiness stems from the deformation of the skin induced by the contact with an object. This mechanical deformation is encoded by mechanoreceptors embedded in the skin tissues and is subsequently interpreted as distinct tactile sensations, which allow environment perception as well as object manipulation. As a consequence, modeling how the skin deforms when subjected to external forces is paramount to understanding the pattern of deformation that leads to specific tactile sensations. Finite-element analysis or analytical models have shown that contact mechanics underpins tactile sensations such as softness or vibrations. However, these approaches are restricted in their ability to generalize: finite-element analysis comprises too many free parameters, and analytical models involve boundary conditions that are too restrictive. In this work, I describe a parsimonious finite-difference model which includes frictional effect and explains skin mechanics with a minimum of four parameters, while retaining a strong predictive power. This 2D-model was validated against several quasi-static and dynamic measurements reported in the literature. The model is both explainable and accurate, making it a powerful framework for predicting the deformation of the skin when being in contact with arbitrary surfaces. This ability has a wide range of applications, from the rendering of artificial tactile sensations to the control of robotic grippers.