Laser Structuring of Open Cell Metal Foams for Micro Scale Surface Enlargement

Nowadays, innovative materials have gained an increasing market share in several industrial fields. One of these novel materials are open cell metal foams. Those can be found in different industrial applications such as in batteries, implants or chemical filters, since high surface-to-volume ratios are needed. In the past, laser technology highlighted the solution for various challenges concerning the performance improvement of open cell metal foams. The performance of several of these properties can be further improved using laser-based fabrication methods allowing the production of repetitive periodic structures on the micrometer or sub-micrometer scale, such as Direct Laser Interference Pattering (DLIP). In this work, DLIP is utilized for structuring the surface of open cell steel foams. By controlling the laser parameters as well as the geometrical arrangement of the beams, 5.2 mm deep structures with a spatial period of 5.8 mm were fabricated. The topography of the used materials is characterized using scanning electron microscopy and confocal microscopy. Finally, the surface enlargement of the DLIP-structured foams are electrochemically characterized by determining the double-layer capacitance using cyclic voltammetry (CV) as well as electrochemical impedance spectroscopy (EIS).