Researchers from North Carolina State University have developed a simple way to convert two-dimensional patterns into three-dimensional (3-D) objects using only light.
“This is a novel application of existing materials, and has potential for rapid, high-volume manufacturing processes or packaging applications,” says Dr. Michael Dickey, an assistant professor of chemical and biomolecular engineering at NC State and co-author of a paper describing the research.
The process is remarkably simple. Researchers take a pre-stressed plastic sheet and run it through a conventional inkjet printer to print bold black lines on the material. The material is then cut into a desired pattern and placed under an infrared light, such as a heat lamp.
The bold black lines absorb more energy than the rest of the material, causing the plastic to contract — creating a hinge that folds the sheets into 3-D shapes. This technique can be used to create a variety of objects, such as cubes or pyramids, without ever having to physically touch the material. The technique is compatible with commercial printing techniques, such as screen printing, roll-to-roll printing, and inkjet printing, that are inexpensive and high-throughput but inherently 2-D.
By varying the width of the black lines, or hinges, researchers are able to change how far each hinge folds. For example, they can create a hinge that folds 90 degrees for a cube, or a hinge that folds 120 degrees for a pyramid. The wider the hinge, the further it folds. Wider hinges also fold faster, because there is more surface area to absorb energy.