Vertical continuous flow lithography for fabricating long 3D structures

We propose an in situ photopolymerization method for three dimensional (3D) microfabrications which we call “Vertical Continuous Flow Lithography” (VCFL). We used a digital micromirror device (DMD) as a dynamic photomask and a vertical flow of polyethylene glycol diacrylate (PEGDA) in a microchannel. VCFL can not only fabricate long (~5 mm) structures but also control 3D geometries of structures. We experimentally demonstrated the fabrication of long fibers whose cross-sectional (diameters and shapes) geometries could be controlled. We believe that VCFL will be useful in bottom up tissue engineering to make long complex structures, such as branched blood vessels.