Design and fabrication of miniature assemblies with SDM processing

Shape Deposition Manufacturing (SDM) produces 3D complex parts through a layered manufacturing process combining material depositions and removals. Thus far, SDM has successfully fabricated intricate parts, much of which is focused on the fabrication of macroscopic artifacts. This research aims to develop the SDM processing technique to fabricate miniature assemblies.; First of all, a new planning algorithm was developed to fabricate mesoscopic functional mechanisms with SDM processing. The development of a new planning algorithm was based upon geometric relationships derived from identified constraints in mesocopic regime. A range of mesoscopic functional mechanisms was effectively fabricated by implementing this new planning strategy. Miniature trailing-edge effectors (MiTEs) for aeroelastic control of Unmanned Air Vehicles (UAVs) are presented in this thesis. These meso-scale mechanisms were built in an assembled configuration with a small clearance of approximately 50 μm.; SDM has been also applied to fabricate microscopic functional parts. SDM has limitations on achievable resolution in the material deposition and removal process. However, SDM has a unique process characteristic due to distinct process steps, which is easy process interruption. Thus, SDM can be interrupted during each process step and integrated with alternative processes. Microfabrication processes have been mostly utilized in this process integration. Through this process integration, micro-scale artifacts with high aspect ratio were fabricated out of different materials such as silicon nitride and polyurethane.; Furthermore, design itself was investigated to evaluate its relevance to downscaling in parallel with the fabrication methodologies. This thesis presents several novel design concepts for miniature functional mechanisms. First, SMA rotary actuators will be discussed as mesoscopic functional mechanisms. These rotary actuators are based on strain gradient variation. Contrary to joint mechanisms, compliant mechanisms are more favorable in micro-scale, considering scaling laws in friction and wear life. Thus, micro-manipulators were developed with structural compliance as a main design parameter. These microscopic mechanisms were mainly developed to visualize the lumen of a human blood vessel, which requires critical features on the order of 10 microns.; In conclusion, these developed methodologies will be evaluated based on experimental results in comparison to outcomes generated from other fabrication processes.