Properties of three-dimensional precision objects fabricated by using laser based micro stereo lithography

Abstract

We demonstrate the properties and fabrication of three-dimensional objects by using laser based mico stereo lithography. A high resolution machining setup for the creation of three-dimensional precision components from a UV-curable photo-resin has been developed. Micro-mechanical arrangements with high geometrical complexity, including movable components are fabricated within a one step production fashion, without the need of assembling individual parts. The layer-by-layer fabrication process is directly based on a user defined, three-dimensional CAD model which will be sliced at a constant increment. For the illumination of individual layers, a frequency-converted diode-pumped solid-state laser is applied, providing high structural surface quality due to a repetition rate of 100 MHz. Specially designed materials from the type ORMOCER® offer a process resolution up to 20 μm in vertical direction. In particular, we present the modification of the resin material and the consequences on the process resolution to achieve the suitability for micro stereo lithography. In order to qualify the production process and its resulting parts in terms of precision and mechanical properties, the produced components have been investigated. The hardness of the generated parts has been determined to more than 1 GPa at a lateral process resolution below 10 μm.