Scanning-projection based stereolithography: Method and structure

• A new hybrid scanning-projection stereolithography method is introduced.
• To show the feasibility of the proposed method, an experimental setup was assembled.
• Scanning is prepared by a programmable motion stage.
• Projection is prepared by a modified DMD projector with digital light processor.
• The repeatability of the process is investigated based on measured result.

Projection-based stereolithography (PSL) is an efficient way for rapid fabrication of 3D structures. However, it is suitable for small parts requiring high resolution. The scanning-based SL (SSL) covers a larger area with a lower resolution. Fabrication time in PSL is intrinsically less than SSL due to exposing an entire image field in a single shot. This study introduces a new scanning-projection based stereolithography (SPSL) to include the advantages of both former methods. SPSL takes advantage of a digital micromirror device (DMD) and a moving stage to combine the projection and scanning methods. The DMD moves continuously over the medium while the projected pattern is continuously updated to allow the fabrication of large layers.After modeling the approach, an experimental setup is assembled to produce real parts. An economical ultra violet light-emitting diode (UV-LED) is used as a light source for curing. Seven 3D models with defined geometry consisted of circular, rectangular, complex and overhanging parts are selected. Five copies of each model are built. The experimental results show that the method is feasible and versatile. The achieved standard deviation is lower than 32 μm.