MIT Media Lab researchers developed software to design and 3D print hair-like structures in bulk. Eventually, the 3D-printed hair could be used as sensors, actuators modeled on the cilia in our own lungs, and even Velcro-like adhesives for robots and other devices.
Their innovation was actually on the software side of the 3D-printing process. From MIT News:
Instead of using conventional computer-aided design (CAD) software to draw thousands of individual hairs on a computer — a step that would take hours to compute — the team built a new software platform, called "Cilllia," that lets users define the angle, thickness, density, and height of thousands of hairs, in just a few minutes.
Using the new software, the researchers designed arrays of hair-like structures with a resolution of 50 microns — about the width of a human hair. Playing with various dimensions, they designed and then printed arrays ranging from coarse bristles to fine fur, onto flat and also curved surfaces, using a conventional 3-D printer…
To demonstrate adhesion, the team printed arrays that act as Velcro-like bristle pads. Depending on the angle of the bristles, the pads can stick to each other with varying forces. For sensing, the researchers printed a small furry rabbit figure, equipped with LED lights that light up when a person strokes the rabbit in certain directions.
And to see whether 3-D-printed hair can help actuate, or move objects, the team fabricated a weight-sorting table made from panels of printed hair with specified angles and heights. As a small vibration source shook the panels, the hairs were able to move coins across the table, sorting them based on the coins' weight and the vibration frequency…
"It's very inspiring to see how these structures occur in nature and how they can achieve different functions," says lead researcher Jifei Ou. "We're just trying to think how can we fully utilize the potential of 3-D printing, and create new functional materials whose properties are easily tunable and controllable."