Seminar in Department of Physics : Implementation of NiTi Shape Memory Materials for Micro-device Applications

Title:  Implementation of NiTi Shape Memory Materials for Micro-device Applications  

Speaker: Dr. Sudhir Kumar Sharma
                Centre for Nano-Science and Engineering
                Indian Institute of Science, Bangalore-560012

Date: 21.02.13
Time: 3.00 p.m.
Venue: L3

Abstract:

Nickel-Titanium (NiTi) shape memory materials has been recognized as the most popular one because they exhibit unique properties such as shape memory effect (SME), tunable mechanical properties and bio-compatibility. NiTi thin-film shape memory alloys (SMAs) have been considered for various applications in MEMS, as they can be patterned using standard lithographic techniques and fabricated in batch processes. In the present investigations, magnetron sputtering of single alloy target has been used for depositing the coatings. Several limitations in the reproducibility and repeatability have been observed with single alloy target sputtering, irrespective of the target composition ratio.

 These limitations have been addressed by designing and fabricating a dedicated Three Target Magnetron Co-sputtering System. The influence of process parameters on film thickness, composition, structure, micro-structure, phase-transformation and mechanical properties has been studied by different analytical techniques and correlations have been established.  The influence of TiN capping layers on the mechanical properties has also been investigated. The fabrication process for NiTi coated micro-cantilevers will be described. The implementation of focused ion beam (FIB) micro-machining techniques to generate high aspect ratio nano-structures will also be explored.