Local annealing of shape memory alloys using laser scanning and computer vision

Moustapha Hafez; Yves Bellouard; Thomas C. Sidler; Reymond Clavel; Rene-Paul Salathe

doi:10.1117/12.405705

6 November 2000 Local annealing of shape memory alloys using laser scanning and computer vision

Moustapha Hafez, Yves Bellouard, Thomas C. Sidler, Reymond Clavel, Rene-Paul Salathe

Proceedings Volume 4088, First International Symposium on Laser Precision Microfabrication; (2000) https://doi.org/10.1117/12.405705
Event: First International Symposium on Laser Precision Microfabrication (LPM2000), 2000, Omiya, Saitama, Japan

Abstract

A complete set-up for local annealing of Shape Memory Alloys (SMA) is proposed. Such alloys, when plastically deformed at a given low temperature, have the ability to recover a previously memorized shape simply by heating up to a higher temperature. They find more and more applications in the fields of robotics and micro engineering. There is a tremendous advantage in using local annealing because this process can produce monolithic parts, which have different mechanical behavior at different location of the same body. Using this approach, it is possible to integrate all the functionality of a device within one piece of material. The set-up is based on a 2W-laser diode emitting at 805nm and a scanner head. The laser beam is coupled into an optical fiber of 60(mu) in diameter. The fiber output is focused on the SMA work-piece using a relay lens system with a 1:1 magnification, resulting in a spot diameter of 60(mu) . An imaging system is used to control the position of the laser spot on the sample. In order to displace the spot on the surface a tip/tilt laser scanner is used. The scanner is positioned in a pre-objective configuration and allows a scan field size of more than 10 x 10 mm². A graphical user interface of the scan field allows the user to quickly set up marks and alter their placement and power density. This is achieved by computer controlling X and Y positions of the scanner as well as the laser diode power. A SMA micro-gripper with a surface area less than 1 mm² and an opening of the jaws of 200(mu) has been realized using this set-up. It is electrically actuated and a controlled force of 16mN can be applied to hold and release small objects such as graded index micro-lenses at a cycle time of typically 1s.

Citation Download Citation

Moustapha Hafez, Yves Bellouard, Thomas C. Sidler, Reymond Clavel, and Rene-Paul Salathe "Local annealing of shape memory alloys using laser scanning and computer vision", Proc. SPIE 4088, First International Symposium on Laser Precision Microfabrication, (6 November 2000); https://doi.org/10.1117/12.405705

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available