Beetling along: Under the influence of moisture, the color of the 3D-printed beetle changes from green to red, and back again to red. (Courtesy: Bart van Overbeeke)
Topics: 3D Printing, Additive Manufacturing, Biomimetics
Researchers in the Netherlands have produced models of a beetle that changes color and a scallop shell that opens and closes in response to changing humidity in the surrounding air. Inspired by iridescent structures in nature, Jeroen Sol and colleagues at the Eindhoven University of Technology showed that they could integrate a specialized liquid crystal into standard 3D-printing techniques, creating “4D printed” devices that react to their changing environments.
Over millions of years, many organisms have evolved micro-scale structures in their anatomies that allow them to change their vibrant iridescent colors in response to stimuli. Recently, researchers have developed inks that change color in the same way and have begun to experiment with incorporating them into 3D-printed structures.
This technology has been dubbed 4D printing, where the fourth dimension represents reversible, time-varying changes to the structures after printing. One widely used technique in 4D printing is to deposit ink directly onto 3D printed structures. This approach can accommodate many types of material, as well as a versatile range of printing temperatures, speeds, and path designs.
4D-printed material responds to environmental stimuli, Sam Jarman, Physics World