Lehrstuhl für Fertigungstechnologie, Universität Erlangen-Nürnberg

Non-thermal Micro-Adjustment by Ultrashort Laser Pulses



Datum: 06.10.2006


Author


Reporter

  • Prof. Dr.-Ing. Dr.-Ing. E.h. mult. Dr.h.c. M. Geiger
  • Prof. Dr.-Ing. F. Vollertsen

Laser micro adjustment is a very versatile and flexible technique for contact free and high accuracy positioning of single components or of systems which already are in assembled state. All laser adjustment processes researched and established up to today are based upon laser induced temperature fields generating targeted stress and strain conditions in the actuator material. Thermally based techniques are however linked to a number of process inherent disadvantages which are gaining in importance especially if miniaturization aspects are involved. Therefore a new, alternative concept of laser micro forming which does not rely on thermally induced tensions is investigated by theoretical and experimental research. As ultrashort laser pulses due to their special physical interaction principles with matter a mostly "cold" laser processing, they represent a suitable basis for the desired process. By non-thermal material removal at specifically suitable process parameters the stress conditions in the actuator sample are changed and a defined and reproducible change in its shape is generated. The process mechanism is based on the mechanical shock impact, which is caused by the fast plasma expansion following the ultrashort pulse irradiation of the samples surface.