A Bright Idea: 3D Printing with Light [Flash Forward Fridays]

Flash Forward Fridays

For the past few decades, technology has been evolving at a blink-and-you’ll-miss-it rate. In this biweekly column, we’ll be peeling back the curtain of the present, and exploring the developing technologies that may soon become the standard in the not-so-distant future.

3D printing is one of the most innovative manufacturing methods to have emerged from the 20th century; its influence can be observed in prototyping, short-run production, and even DIY applications.

In addition to the standard industrial applications like medical devices and machine components, this form of additive manufacturing is always full of surprises, with people using it to print everything from food to fashion and self-assembling objects. Some 3D printers can even replicate themselves.

However, in spite of this versatility, 3D printing is not without its limitations. One of these limitations is that the process itself, which works by depositing layers of material onto a base or other surface, can sometimes result in an unfinished-looking object with ragged and ridged edges.

3D Printing gets a Luminous Upgrade

Recently, a research team from the University of California, Berkeley in collaboration with the Lawrence Livermore National Laboratory developed a completely new approach to 3D printing. Dubbed computed axial lithography (CAL), this method utilizes volumetric printing technologies instead of relying on the traditional layer-by-layer mechanisms.

Hayden K. Taylor, assistant professor of mechanical engineering at the University and one of the authors of the research paper, explained volumetric printing as being a “category of additive manufacturing where all points inside a 3D object are materialized or created pretty much simultaneously as opposed to building up the geometry layer by layer.”

Sounds cool, but what does that mean, and how is it even possible?

In a YouTube video, the team demonstrated the process using a miniature replica of Auguste Rodin’s iconic Thinker sculpture. Inspired by how CAT scans work, the team used tomography to capture a series of images of the replica from every angle. They stitched these images together to create a video, which was then fed into a digital light processing (DLP) projector.

The images were projected via light onto a rotating jar of a photopolymer, a type of resin that transforms its properties when exposed to certain amounts of certain kinds of light. Once activated by the light, the resin began to cure in the shape of the Thinker replica.

The Next Step in Additive Manufacturing

Unlike other forms of additive manufacturing, this method allowed researchers to print objects in their entirety at once, which not only sped up the process but also improved the aesthetic by removing the ridged effect that layer-by-layer construction sometimes leaves behind.

However, one of the most exciting aspects of 3D printing with light is that it makes overprinting, aka, the ability to print an object around an existing object to create a complex assembly entirely possible. The team was able to use this method to make a screwdriver by printing the handle around the metal shank of the screwdriver.

While this kind of game-changing innovation has the power to transform the way objects are designed and manufactured, the idea is still very new and far from use on a wide scale.