Research

The tangible impact of MIT’s 3D printed hairs

The MIT Media Lab at Massachusetts Institute of Technology (MIT) is renowned for applying 3D printing to some of the most unusual and inspired projects.

Artist, architect, glass 3D printer and Stratasys partner Neri Oxman leads the lab’s Mediated Matter Group. And Neil Gershenfeld, Director of the lab’s Center for Bits and Atoms, founded Fab Labs. The Tangible Media Group is another example of the lab’s often blue-sky expertise. Led by Professor Hiroshi Ishii, MIT Jerome B. Wiesner Professor of Media Arts and Sciences, Tangible Media seeks to “seamlessly couple the dual world of bits and atoms by giving dynamic physical form to digital information and computation.” In other words, the lab seeks to make digital data physically interactive.

Cilllia, is just one example of the Tangible Media Group’s innovative work using 3D printing. As the name suggests, this project is an extension of the structure and the purpose of hair.

3D printed Cilllia actuate movement in a small weight. Image via Tangible Media Group/MIT
3D printed Cilllia actuate movement in a small weight. Image via Tangible Media Group/MIT

Pixel-by-pixel

In Cilllia Tangible Media Group scientists developed a pixel-based hair geometry. Not only does this design rend the models 3D printable, it also facilitates an ability to modify each strand by adding more pixels variously, to change the height, thickness, angle and profile.

Changing the structure of hairs by the pixel. Image via Tangible Media Group/MIT
Changing the structure of hairs by the pixel. Image via Tangible Media Group/MIT

In addition to modifying the artificial 3D printed hairs by the pixel, Cilllia also experiments with their arrangement. As demonstrated in the diagram below, the group tried linear horizontal, linear diagonal, curved arch, curved waves and curved circular arrays of 3D printed hairs, each relating to a different potential movement.

When used as an actuator, these different directional arrays generated different movements in an object. Image via Tangible Media Group/MIT
When used as an actuator, these different directional arrays generated different movements in an object. Image via Tangible Media Group/MIT

Why 3D printed hairs?

More than a mere investigation of SLA-3D printable shapes, Cilllia applies these varied parameters to develop a range of possible applications for the structures. In one instance, 3D printed hairs are used to conduct phone vibrations and convert them into the rotation of a windmill. In another, Cilllia at the base of ballerina figurines are used to make them “dance” when music is played.

It also turns out that artificial hair can make a great adhesive, and switches. With a hairy surface the team to create a type of acoustic sensor that, when connected to Piezo microphone, can be used to switch on a light. Explaining this particular application, the researchers write, “One of the most important features of hair in nature is the extent to which it aids in sensing changes in environmental conditions. Many animals, such as caterpillars, use hair on their skin to detect airborne disturbances.”

“In the engineering world, researchers have been learning from hair structure to build artificial flow sensors. Building those sensors usually requires expensive machines and microfabrication processes. We utilize the ability to control the hair geometry of Cilllia combined with an acoustic sensing method to rapidly fabricate sensors that detect the direction and velocity of human swiping.”

Cilllia – 3D Printed Hair Structures for Surface Texture, Actuation and Sensing from Tangible Media Group on Vimeo.

Further reading 

A paper describing project Cilllia was published in the Proceedings of the 2016 CHI Conference and is co-authored by Jifei Ou, Gershon Dublon, Chin-Yi Cheng, Felix Heibeck, Karl Willis and Hiroshi Ishii.

Other work from the group includes the Materiable project, in which actuators and sensors are applied to a block of 3D printed pixels. When these pixels are touched they react and ripple like water, and correspond to a projection of light. Since then Ishii, and colleagues Daniel Leithinger, David Lakatos, Anthony DeVincenzi and Matthew Blackshaw have been granted a patent for this method and apparatus. Recently, Ishii also oversaw a project to create a bacteria-activated cooling suit for runners.

Ou and Willis, other Cilllia co-authors, have patented a method of designing 3D printed auxetic structures, which is assigned to award winning 3D software company Autodesk.

Another project looking to enhance the capabilities of hair-like structures is Georgia Tech’s 3D printed cat tongues. For what purpose? For untangling fur of course.

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Featured image shows 3D printed Cilllia. Image via Tangible Media Group/MIT