Digital Micromirror Device Based Microstereolithography for Micro Structures of Transparent Photopolymer and Nanocomposites

This paper describes a Digital Micromirror Device (DMD) based ultraviolet (UV) microstereolithography (µ-SL) system developed for rapid prototyping and manufacturing of micro 3D structures. Characterization experiments show that the developed the DMD-based imaging system irradiates an entire photopolymer layer at once, providing reasonable curing speed and good resolution at a low cost. 2D and 3D micro parts were fabricated. High frequency ultrasonic vibration (above 20 kHz) was experimented and verified that it can be used to significantly decrease the leveling time of viscous photopolymer. Furthermore, micro parts were also fabricated in nanocomposites, which were obtained by ultrasonic mixing of the transparent photopolymer and nano-sized ceramic particles. High quality micro models fabricated by this novel process could be used for micro scale investment casting, tooling, devices, and medical applications.