Micro-rapid-prototyping via multi-layered photo-lithography

Rapid prototyping (RP) is widely used for part fabrication in the normal scale. For fabrication in micro-scale applications such as integrated circuit (IC), micro-electro-mechanical system (MEMS), methods such as surface and bulk machining are commonly used. This paper introduces a micro-fabrication technique using the RP principle, i.e., layered manufacturing, combined with mask-based micro-lithography, which is usually used in semiconductor industry. An ultraviolet (UV) excimer laser at the wavelength of 248 nm was used as the light source. A single piece of photo-mask carrying various patterns of multiple layers obtained from slicing a three dimensional (3D) micro-parts was employed for the lithography process. The preliminary results show that a certain RP photopolymer can be applied for the micro-RP, and solid layers with sharp edges can be formed from the liquid photopolymer identified. Using a unique alignment technique, a five layered gear of 1 mm in diameter has been successfully fabricated using the proposed method .