Figure 4.

Mechanical characterization of 3D printed patches. (a,b) Images of 4A1CNF before stretching and 50% elongation under tensile tests. (c) Stress-strain curve of two samples under a ramped fore rate of 0.1 N/min. (d) Young’s modulus from the slope in the initial linear region of the stress-strain curve for two samples. (e) Maximum elongation of sample right before the samples fractured. Cycling loading in DI water to assess the hysteresis, deformation over cycling that mimics the movement in the skin for (f) 2A4CNC and (g) 4A1CNF. The sample was scratched repeatedly for 100 cycles at strain ramp 10%/min to 20% strain. (h) Hysteresis versus the number of cycling from the stress-strain curve of the inside area of loading and unloading.