Imagine a material that changes color when stretched, twisted, or squeezed—like a chameleon reacting to touch.
Thanks to a major breakthrough by scientists from Penn Engineering, Harvard, Duke, UC Berkeley, and Lawrence Livermore National Laboratory, this futuristic idea is now a reality.
The team has developed a new way to 3D print a unique material called cholesteric liquid crystal elastomers (CLCEs), bringing these color-changing materials into the world of three-dimensional design for the first time.
CLCEs are soft, rubber-like materials that shift color when under stress.
This ability comes from their spiral-shaped inner structure, which reflects light in special ways—similar to how beetle shells or butterfly wings shimmer.
Until now, these materials were mostly limited to flat, two-dimensional surfaces like LCD screens. The team’s new method allows them to be printed in 3D forms, opening up exciting new uses in wearable tech, robotics, art, and sensors.
The printing technique, called Coaxial Direct Ink Writing (DIW), was originally co-developed over a decade ago.
But applying it to CLCEs wasn’t easy. The material is thick and sticky, making it hard to push through a printing nozzle while keeping its special light-reflecting structure.
To solve this, lead author Alicia Ng, a Ph.D. student at Penn Engineering, helped develop a smart solution.
Her team surrounded the CLCE core with a transparent silicone shell. This shell worked like scaffolding—strong enough to hold the shape, but flexible enough to preserve the material’s color-changing abilities.
The result is a 3D-printed material that keeps its dazzling visual effects and can be shaped into complex designs, like lattices, wraps, and filaments.
These structures can react in real time to physical changes, offering visual cues to movement, pressure, or stretching. For example, a wearable device made from this material could show changes in color if a body part swells, giving instant feedback in healthcare settings.
It could also be used in robotics, such as grippers that indicate how much pressure they’re applying, or in smart fabrics that monitor mechanical stress.
The team believes these materials could eventually go even further. They are exploring ways to combine CLCEs with other types of smart materials that respond to temperature or light. They’re also looking to nature for eco-friendly inspiration, such as using elements from biofilms to create self-repairing or biodegradable versions.
With the ability to print directly onto curved surfaces—like human skin or flexible robots—this technology could lead to the next generation of responsive, intelligent materials.
The researchers are also working on systems that can learn from how the material behaves, leading to “sentient” structures that can sense, adapt, and even redesign themselves over time.
This 3D printing breakthrough turns science fiction into something tangible—offering a glimpse into a future where materials aren’t just passive objects but active participants in our world.
Source: University of Pennsylvania.
