Development And Analysis Of DMD-based Microstereolithography System

Micro scale 3D complex structures are critical for performance of Micro Electro-mechanical Systems(MEMS), but it still remains a challenge for traditional micro-fabrication technique. Projection micro-stereolithography can fabricate micro scale 3D complex structures with high resolution. At present, projection micro-stereolithogrphy is regarded as one of the most promising micro-stereolithograpy techniques to fabricate micro parts.In this paper, we developed a dynamic mask projection micro-stereolithography system, it used Digital Micro-mirror Devices as dynamic mask, and adopted LED array as light source, which spectral band can match with the absorption spectra of the resin. To fabricate microstructures with high viscosity composites, we designed new vat and coating system. Additional, a new direct slicing method of CAD model based on AutoCAD and control software of the system based on LabVIEW are proposed.It is shown that the lateral resolution of the SL system is determined not only by the optical resolution, but also by the chemical response of the photo curable resin. From the measured values of the optical system's resolution and the composites'working cure, we know that the lateral resolution of our system is 14 micrometers. The influence of oxygen and the method eliminated oxygen inhibition were studied; some preliminary experiments were experienced and a micro-gear was fabricated successfully by projection micro-stereolithography system developed by ourselves.