Multiple Material

We have previously described the development of a μSL system using a Digital Micromirror Device (DMD) for dynamic pattern generation and an ultraviolet (UV) lamp filtered at 365 nm for crosslinking the photoreactive polymer solution. The μSL system was designed with x-y resolution of ~2 μm and a vertical (z) resolution of ~1 μm (with practical limitations on vertical resolution of ~30 μm resulting from the current laboratory setup). This μSL system is capable of producing real threedimensional (3D) microstructures, which can be used in micro-fluidics, tissue engineering, and various functional micro-systems. As has been explored and described in μSL, many benefits will potentially be derived from producing multiple material microstructures in μSL. One particular application area of interest is in producing multiple material micro-scaffolds for tissue engineering. In this work, a method for multiple material μSL fabrication was developed using a syringe pump system to add material to a small, removable vat designed for the μSL system. Multiple material fabrication was accomplished by manually removing the vat and draining the current material, rinsing the vat, placing the vat back into the system, and dispensing a prescribed volume in the vat using the syringe pump. Layer thicknesses less than ~30 μm were achieved using this process. To demonstrate this system, several multiple material microstructures were produced, and we believe multi-material μSL represents a promising technology for producing functional microstructures with composite materials.