Multiple Material Micro-Fabrication: Extending Stereolithography to Tissue Engineering and Other Novel Applications
A design for modifying an existing 3D Systems stereolithography (SL) apparatus 250/50 was developed to accommodate multiple material fabrication for building multi-material, multifunctional and multi-colored prototypes, models and devices. The machine was configured for automated access to an intermediate washing, curing, and drying unit that eliminated contamination between material vats and maintained accurate platform registration throughout the build process. Three vats were arranged on a rotating vat carousel, and each vat was adapted to actively maintain a uniform, desired level of material by including a recoating device and a material fill and removal system. A single platform was attached to an elevator mechanism (zstage) to traverse the platform to and from the vats and the washing, curing, and drying unit. The platform was mounted to the z-stage via an automated rotary stage to rotate the platform about a horizontal axis, thus providing angled building, washing, curing, and drying capabilities. A horizontal traversing mechanism was also designed to be optionally included to facilitate manufacturing between multiple SL cabinets, related SL apparatuses and/or other alternative manufacturing technologies. For micro-fabrication, linear and rotary stages were selected that provided ±1.0 µm repeatability and 0.1 µm resolution and ±2 arc sec repeatability and 0.13 arc sec resolution, respectively. The multi-material SL design presented here is capable of utilizing existing SL resins for manufacturing multiple material mechanically and electrically functional models as well as hydrogels, biocompatible materials, and bioactive agents for a variety of biofunctional, implantable tissue engineering applications including nerve regeneration and guided angiogenesis.