Product Code: ICA13_M906

Laser Patterning of Thin Film Strain Gauges
Authors:
Oliver Suttmann, Laser Zentrum Hannover e.V.; Hannover USA
Jan F. Duesing, Laser Zentrum Hannover e.V.; Hannover Germany
Juergen Koch, Laser Zentrum Hannover e.V.; Hannover Germany
Ludger Overmeyer, Laser Zentrum Hannover e.V.; Hannover Germany
Presented at ICALEO 2013

Current trends of intelligent products and controlled processes show an increasing need for long-living sensors. Metal thin-film strain gauges are suitable for monitoring mechanical loads over the entire lifetime of a component. However, existing manufacturing methods can only pattern these gauges on flat components and in large quantities to ensure an economical process.
To overcome these limitations, a patterning process based on ablation using picosecond laser pulses has been developed and is the subject of this paper. Starting with the analysis of the ablation behavior of the sensing layer, a phenomenological model capable of describing the ablation geometry was developed. The process window of the patterning process was characterized and a parameter for the quantitative description of the process reliability defined.
The method developed is an important prerequisite for the integration of thin-film strain sensors on 3-D surfaces for products such as bearings, or in products which are typically manufactured in small quantities, such as medical implants.