Thin film implants based on magnesium alloys

Magnesium alloys are of great interest for the application as temporary implant. Magnesium is an essential element in the human metabolism. Furthermore, it is biocompatible and biodegradable which makes it an interesting material for implants that should stay only for a defined time period in the human body of the patient (biodegradable implants). However, pure magnesium offers only limited material properties (e.g. corrosion rate, mechanical properties). Consequently, other elements are combined with pure magnesium to tailor the material properties and have an additional therapeutic effect. Elements to alloy pure magnesium could be e. g. silver, chromium, lithium and zinc.

This project focuses on thin film sample which usually have only a thickness up to some 10 µm. A combination of magnetron sputtering and UV lithography is used to fabricate the thin film samples. This technique is favorable to achieve thin films in all different kind of shapes.

In the beginning of this project, magnesium silver is investigated. This material combines the biodegradable properties of magnesium with the antibacterial properties of silver. Different magnesium silver concentrations/alloys will be investigated related to the change of material properties during the project. Mechanical properties will be investigated using tensile test, whereas the microstructure will be determined with Scanning Electron Microscopy, X-Ray and Transmission Electron Microscopy. Preliminary corrosion experiments will show how the silver content influences corrosion properties. Further corrosion measurements (e.g. related to cell influence) will be done in cooperation with Reneé Unbehau (P1b).