It seems like 3-D printers are the perfect replicator technology. Enter a shape. Hit a button. And layer by layer, it will become pristine, shaped matter. But the realities of 3-D printing are more complicated. The machines and their extruded materials don’t circumvent physics. A wrongly angled arc can bend or collapse. And really fine detail work, like threads of hair, can be impossible to produce.
But a team from Carnegie Mellon–led by Gierad Laput, the same PhD student who worked on the wild iPhone audio experiment Accoustraments–has developed a method to reliably teach a 3-D printer to create hair–from the soft, flowing locks of a toy pony’s tail, to the short bristles of a scrub brush–without changing the hardware or the polymers inside the printed plastic.
“Yes, they are strokable,” Laput says. “Surprisingly, with enough strands, the extruded strings actually feel like real hair! I mean they are synthetic, but the printed strands feel like actual strands of hair…and because they feel like actual strands of hair, we can perform post-processing manipulations like cutting, curling, or even braiding.” That said, the 3-D-printed human wigs would be both prohibitively expensive, and require a massive printer.
To develop this new technique, Laput figured out that by dropping small piles of molten plastic at various heats, then pulling the printer head away at just the right speed, make it possible to stretch the goo as it cooled to create strands similar to those crafters see using a hot glue gun. The parameters can be set within a 3-D printer’s standard G-Code (which, yes, is generally hidden from a user’s view) to be repeatable with robotic precision.
“Like any ‘making’ craft, knowing little bits of details about how something works opens up a ton of possibilities,” Laput says. “The fabrication research community is doing a ton of things to go beyond just simply telling a 3-D printer to extrude a shape.” Indeed, his project in particular leads to some interesting implications of 3-D printing. We tend to view the printers as standard platforms. But Laput has developed a new technique to turn his own printer into the equivalent of a more advanced artisan. As a researcher, anyone can snip his code in a published paper to reproduce the effects. However, if Laput were an artist, or a businessman, it’s easy to imagine him keeping this technique for himself, just like the closely guarded trade secrets of old blacksmiths or watchmakers.
In the future, Laput would like to push his technique to create finer hair (like fur) or even 3-D printed Velcro. And like Accoustraments, he’d like to see how human touch and conductivity could make these objects more interactive.