Selective laser sintering of ultra high molecular weight polyethylene for clinical applications

Rapid prototyping is a relatively new technology, which although prominent in the engineering industry is only just starting to make an impact in the medical field. Its current medical uses are mainly confined to surgical pla nning and teaching, but the technology also has the potential to allow for patient-tailored prostheses. The work reported here describes the applicati on of a simplified selective laser sintering apparatus with ultra high mole cular weight polyethylene (UHMWPE). The morphology and chemistry of the sta rting powders and lased material have been characterized using Fourier Tran sform Infra Red spectroscopy and a combination of light and scanning electr on microscopy. It was found that solid linear continuous bodies could he fo rmed, but material shrinkage caused problems when trying to form sheet-like structures. The porosity of the formed material was also a concern. The ma terial exposed to the laser beam was shown to have undergone degradation in terms of chain scission, cross-linking, and oxidation. It has been conclud ed that to apply this technology to the fabrication of UHMWPE devices requi res the development of improved starting powders, in particular with increa sed density. (C) 2000 John Wiley & Sons, Inc.