Smart materials: Opportunities and applications in some fields

Abstract

In the first part of this paper, a short introduction to the mechanism of shape memory alloys (SMAs) is given and especially the NiTi alloys are described. Some examples for the application of these materials are presented. One is a quick changing actuator in a car safety system. Some examples of different safety systems in modern cars are described and the material development of an adaptive safety system with SMAs is explained. Through the spontaneous conversion of the SMA when exceeding a critical temperature, a very fast and functional secure linear movement can be performed. It should be possible to implement SMAs with long time stability. Quick heating systems have been developed for this purpose to enable a quick and safe heating of the SM elements by using the actual current network system on board. In the second part, a newly-developed intramedullary nail with a device made of SMAs used for limb lengthening is presented. The benefit of such an alternative device is described, together with the details of the design. The use of smart materials in mechanical design offers benefits such as lower complexity of the device and closeness to bionic structures.

Keywords:

• Smart materials
• shape memory alloys
• actuators
• bone lengthening systems
• medical implants
• passenger safety system
• NiTi alloys

Additional information

Notes on contributors

P Gümpel

Prof Paul Gümpel is director of the Material Testing Laboratory at the HTWG Konstanz and scientific head of the WITg Institute in Switzerland. He is a board member of a multitude of associations, such as GCMM, VDI and DGM. His specialties are corrosion research on stainless steels and smart materials. He has published more than 160 papers, books and patents.

J Strittmatter

Joachim Strittmatter has worked at the HTWG Konstanz in the Material Testing Laboratory since 1994, mainly on R&D projects with shape memory alloys. Since 2002, he has also worked at the WITg in Switzerland, where he is responsible for Intelligent Materials. He is member in the technical committee “Unconventional Actuating Elements” of the GMA within the VDI/VDE. He is the author or co-author of 21 papers.