Table of Contents
Journal of Metallurgy
Volume 2011 (2011), Article ID 501483, 15 pages
http://dx.doi.org/10.1155/2011/501483
Review Article

Biomedical Applications of Shape Memory Alloys

Politecnico di Milano, Laboratory of Biological Structure Mechanics, Department of Structural Engineering, Piazza Leonardo da Vinci 32, 20133 Milan, Italy

Received 16 December 2010; Accepted 8 March 2011

Academic Editor: Stefano Gialanella

Copyright © 2011 Lorenza Petrini and Francesco Migliavacca. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Shape memory alloys, and in particular NiTi alloys, are characterized by two unique behaviors, thermally or mechanically activated: the shape memory effect and pseudo-elastic effect. These behaviors, due to the peculiar crystallographic structure of the alloys, assure the recovery of the original shape even after large deformations and the maintenance of a constant applied force in correspondence of significant displacements. These properties, joined with good corrosion and bending resistance, biological and magnetic resonance compatibility, explain the large diffusion, in the last 20 years, of SMA in the production of biomedical devices, in particular for mini-invasive techniques. In this paper a detailed review of the main applications of NiTi alloys in dental, orthopedics, vascular, neurological, and surgical fields is presented. In particular for each device the main characteristics and the advantages of using SMA are discussed. Moreover, the paper underlines the opportunities and the room for new ideas able to enlarge the range of SMA applications. However, it is fundamental to remember that the complexity of the material and application requires a strict collaboration between clinicians, engineers, physicists and chemists for defining accurately the problem, finding the best solution in terms of device design and accordingly optimizing the NiTi alloy properties.