CMU and Disney researchers create 3-D printed optics

Researchers at Carnegie Mellon and Disney Pittsburgh develop toys that utilize the technology of 3-D printing. (credit: Todd Medema/Junior Photograph) Researchers at Carnegie Mellon and Disney Pittsburgh develop toys that utilize the technology of 3-D printing. (credit: Todd Medema/Junior Photograph)

With the development of novel 3-D printed optics, magic comes to life at Carnegie Mellon inside the Disney Research Pittsburgh lab.

Behind the closed doors of the Robert Mehrabian Collaborative Innovation Center, members of the Disney and Carnegie Mellon communities are conducting various projects and creating innovative technologies that would enhance the entertainment experience of Disney’s amusement parks.

Three-dimensional printing is a manufacturing process in which an object is created, or “printed,” one layer at a time. Using a printing liquid that cures quickly, the printer creates the object pass-by-pass per the desired geometry provided by a computer program. Even though 3-D printers were introduced in the ’80s, new technologies and reduced costs have allowed research to expand.

For example, multiple materials can be printed into one object. This property broadens the range of 3-D printing’s applications by increasing the level of complexity a printed structure can have.

The Disney Research website describes printed optics as, “A new approach to creating custom optical elements for interactive devices using 3-D printing.” Optics refers to the behavior and properties of light, and manipulating light is important to an entertainment company such as Disney. The uses range from the experience someone gets walking through a room to an interactive digital display.

On the team researching printed optics are Karl D.D. Willis, a Ph.D. candidate in computational design; adjunct professor of architecture Eric Brockmeyer; Human-Computer Interaction Institute professor Scott E. Hudson; and Ivan Poupyrev, a Disney senior research scientist.

The researchers’ optical elements are printed from transparent plastic, and they use bubbles to manipulate light. Bubbles added inside the plastic during printing reflect light within the display to reveal internal patterns or text.

To direct light, the group developed light pipes, which resemble optical fibers. Because multiple materials allow one to create structures within structures, light pipes made from transparent plastics can be printed within the greater structure, and they offer a wider range in lighting displays than optical fiber can.
When describing the versatility 3-D printing has to offer, Willis said, “There’s really no other technology that...can make clear material that is arbitrary geometry and arbitrary shapes on the inside.”

The team used a toy with light-up and moving eyes as an example of this technology’s applications. By redirecting images projected in the toy’s base through its body, the team has created a light display in a children’s toy without LEDs, batteries, or circuits. This simplicity highlights another advantage of 3-D printing: Everything is printed in one piece, not made up of multiple parts.

A printed structure is still currently more expensive to produce than a similar product assembled from pieces. The researchers, however, stressed that the goal of this research is not about mass production, but about customization.

“We’re really not trying to compete with [commercial] technologies,” Brockmeyer said, “But sort of trying to realize what additive manufacturing can provide that is different from those manufacturing.”

In addition to manipulating the properties of light, their research involves utilizing light to give toys different capabilities. If pieces are inserted into the object mid-print, like an LED or infrared emitter/receiver pairs, the object can detect light in addition to refracting it. This ability allows the technology to expand to sensors.

The possibilities are far and wide — with its versatile and customizable nature, this technology surpasses traditional optics and is limited only by one’s imagination. Printed optics would make any geek agree with Disney: “Dreams do come true.”