Micro-scale free surface rapid prototyping

Summary form only given. IC-based micromachining processes used to fabricate MEMS devices have certain limitations. First, most of the IC-based micromachining processes cannot be used to fabricate complex 3D micro parts with high aspect ratios. Second, only a few semiconductors and other materials can be processed by the current IC-based micromachining for MEMS; Many other important engineering materials, such as smart ceramics and functional polymer cannot be easily incorporated into MEMS. A novel microfabrication process, constrain surface micro stereolithography, was introduced to fabricate high aspect ratio and complex 3D microstructures (Maruo et al., 1997). However, the constrained surface method used has generated many inherent problems such as layer sticking defects (Maruo and Kawata, 1997). A free surface micro stereolithography (/spl mu/SL) method is developed. Sophisticated 3D parts can be made by scanning a UV beam on the liquid monomer resin, curing the resin into solid polymer in a layer by layer fashion (1-10 /spl mu/m in thickness), and stacking together all layers with various contours. In contrast to conventional subtractive micromachining, the micro stereolithography is an additive process, which enables one to fabricate high aspect ratio microstructures with novel smart materials.