3D printing produces human-hairlike bristles

Slowly but surely, researchers are stripping away the limitations of 3D printers.

Until now, dense and finely featured objects had been considered off-limits, simply because the computer-aided design (CAD) files required would be enormous and take hours to compute. But new software designed by researchers at the MIT Media Lab circumvents this problem.

Called Cilllia, it uses sliders to let users create surfaces covered in thousands of hairs with a resolution of 50 microns, about the width of a human hair. Unlike CAD, where each hair has to be drawn individually, this process takes just a few minutes.

"[Hair] comes with a challenge that is not on the hardware, but on the software side," said first author Jifei Ou, an MIT graduate student in media arts and sciences, in a statement.

Cilllia uses sliders that allow quick changes to the parameters of the hair structure, with a real-time visual representation. The user can adjust height, thickness, profile and angle, as well as the quantity of hair on a structure. The software can even be used to create curved hairs in a spiral pattern.

The result is a program that can be easily used to create brush structures in various forms using stereolithography 3D printing. The team made paintbrushes, Velcro-like pads that stick to each other, hair-based actuation, and a furred toy bunny that lights up green when you stroke it correctly.

It's the latest advancement in 3D printing, an industry that will be worth just over $20 billion by 2019, according to Canalys.

"The ability to fabricate customized hair-like structures not only expands the library of 3D-printable shapes, but also enables us to design alternative actuator and sensors," the team's paper, presented at the Association for Computing Machinery's CHI Conference on Human Factors in Computing Systems in May, concluded. "3D-printed hair can be used for designing everyday interactive objects."