This research introduces a new class of additive manufacturing technique for support-free printing. This process uses an array of ultra-violet (UV) laser diodes to immediately cure the jetted photopolymer at the laser intersection; thus, achieving rapid solidification. A prototype system using 405 nm laser array with a jetting device consisting of a piezoelectric pump and a solenoid pin was designed and built. A control scheme for the constructed prototype using traditional machine language was established. Photopolymers used for the experiments were characterized by identifying two dominant properties, penetration depth and critical exposure, by Jacob's working curve method, called windowpane test based on Beer-Lambert's law of exposure. To find a proper range of the printing speed and flowrate, a process model for the proposed printing technique was created by adapting Jacob's model as well as defining the geometry feature deposition model. Using a printing speed of 1 mm/s for a flow rate of 0.5 mm3/s, it was confirmed to create the structure having up to 90-degree overhanging, and a 60-degree overhanging structure can be repeatedly printed with commercially available photopolymers. The study also reveals and discusses the challenges associated with fluid behaviors in such a dynamic condition.
