Boston Micro Fabrication uses projection micro stereolithography (PµSL) for microfabrication in 3D printing. This digital micro-display technology provides stereolithography masks that work as virtual photomasks. This technique allows for rapid photopolymerization of an entire layer with a flash of UV illumination at micro-scale resolution. The mask can control individual pixel light intensity that allows control of the material properties of the fabricated structure with spatial distribution.