Inverted multi-material laser sintering

We present an additive manufacturing process that uses an upward-directed laser to fuse a monolayer of powder onto a substrate through a clear surface. The process is then repeated to build a hanging part layer by layer, by replenishing powder on the glass, or moving to a second plate with a different powder. Our process eliminates the need for a large powder bed as well as allows the sintering of different powders in a single layer. We demonstrate this method by using a 445 nm laser to fabricate a multi-material pattern of Nylon-12 and TPU. We characterize the mechanical properties of the fabricated composite and discuss advantages and disadvantages of this approach.