Comparison of medical-grade ultrahigh molecular weight polyethylene microstructure by atomic force microscopy and transmission electron microscopy.

Atomic force microscopy is used to image the topography of surfaces of bulk medical-grade ultrahigh molecular weight polyethylene (UHMWPE). Comparison with transmission electron microscopy images demonstrates that the AFM can resolve the plate-like stacks of crystalline lamellae characteristic of UHMWPE without aggressive surface treatment. Surface preparation for the AFM must be carried out by cryomicrotomy at extremely low temperatures to prevent smearing of surface features. Chemically-etched surfaces of UHMWPE require substantially less surface preparation for AFM imaging.