Study on surface indentation and fractal characteristics of biomedical micro-nano fibers

Abstract In this paper, biomedical micro-nano polycaprolactone (PCL) fibers were prepared by electrospinning technology. The surface structure and microcosmic characteristics of the PCL fibers were characterized by scanning electron microscope and atomic force microscope, and nanoindentation tests were carried out on the fiber surface by atomic force microscope. The experimental results show that the elastic modulus of the fiber increases with the decrease in indentation depth. A mathematical model of the surface indentation process of biomedical micro-nano fibers was constructed based on statistical fractal theory. The fractal parameters of the material were obtained by fitting the experimental curves, and this model can effectively simulate the size effect of polymer fiber materials in nanoindentation experiments.