Electromagnetic Embossing of Optical Microstructures

Abstract

Electromagnetic forming (EMF) is a highspeed forming process that is already established in the macroworld. Due to its advantages like high deformation rate and cheaper tools, it is introduced to microforming. In this research, the replication of prismatic optical microstructures is investigated. EN AW1050A (Al99.5) micrometal sheets with a thickness of 50 خ¼m and 300 خ¼m are electromagnetically microembossed. With this technique, it is possible to successfully replicate triangular cross section micro Vgrooves of 86.6 خ¼m in width and 24.1 خ¼m in depth with an average surface roughness of Sa = 44 nm. The microstructures of the embossing tool are generated by diamond micro chiseling (DMC), a novel machining process to produce microstructures with discontinuous geometry, like miniature cube corner retro reflectors and Vgrooves with welldefined endings.