Variation of the Penetration Effort in an Artificial Tissue by Hypodermic Needles

Figure 3

SEM photos of the spine and analysis of penetration and removal forces in muscle tissue. Source: Cho et al. [11]. Note: A—North American porcupine thorn. B and C—images showing the microstructure of the tip and tip base, respectively. D—the fluorescence image that allows the visual delineation of the geometry of the scales. E—image showing the microstructure of the tip of the porcupine’s spine. F—the representative plots of force versus extension show puncture, penetration, and removal of scaleless, nonscaled spine and African porcupine from tissue (scale bars: 100 μm). The red arrows indicate resistance to tissue removal (not observed in others). G—summary of experimental values obtained from the penetration/removal of the scaly, scaleless, G 18 needle and African porcupine spine. Source: Cho et al. [11].