Needle Penetration Through Polymeric Cellular Foam Materials

This article presents an analytical model for predicting the needle penetration force through relatively hard polymeric cellular foam. Prediction of needle penetration force is of importance to a number of applications, including textile and composites manufacture as well as robotic surgery. With the aid of this analytical model, a complete nonlinear force-displacement relation can be predicted for any needle size, material hardness, thickness, or inclination. The model assumes the needle to be a cylinder with a conical tip and ignores features, such as needle eye. The primary mechanism for needle penetration force is cell crushing while the friction between the needle and the foam plays a secondary role. There is a good agreement between the experimental and analytical force-displacement curves. In comparison to numerical methods that require nonlinear finite element analysis, this analytical model can be implemented with the knowledge on only two material properties: compression strength and frictional resistance.