Measurement of mechanical properties of nanometer scale polymer structures using atomic force microscope

One-dimensional nanofibers of Poly(vinyl alcohol) (PVA) were reinforced by adding biomolecular ferritin nanoparticles. The PVA/ferritin composite nanofibers with diameters around 100 nm were oriented on AFM calibration grating by a modified electrospinning method. The elastic modulus of the nanofibers was tested in three points bending by applying AFM force-curve measurement. The PVA/ferritin nanofibers revealed the enhanced elastic moduli about 2 times higher than those of pure PVA nanofibers. It is suggested that the enhancement of the elastic modulus by ferritin is attributed to hydrogen bondings formed between the peptide chains of the ferritin shell and the PVA matrix. The PVA nanofibers reinforced by ferritin may be applicable to artificial muscles and actuators.