Scientists at the Swiss Federal Institute of Technology Lausanne (EPFL) have developed a soft, rubber-like material that can be easily 3D printed while also being remarkably tough and durable.
The discovery could help improve the performance and lifespan of products ranging from soft robots to wearable electronics and medical devices.
The research, published in Science Advances, builds on an earlier breakthrough made by the same team in 2024.
At that time, the researchers created a new type of material called a double network granular elastomer, or DNGE.
It was originally designed as a special ink for 3D printers, allowing engineers to produce flexible objects with carefully controlled mechanical properties.
As the team continued studying the material, they made an unexpected discovery. The same internal structure that makes DNGEs easy to print also gives them an unusual combination of strength and durability.
This is important because soft materials, known as elastomers, usually face a difficult trade-off. Some are very resistant to breaking when stretched or hit with sudden force, but they gradually weaken after repeated bending or stretching. Others can withstand millions of repeated movements without wearing out but tear easily when placed under heavy stress.
The new material appears to overcome this long-standing problem.
According to the researchers, the secret lies in the material’s unique internal design. DNGEs contain tiny rubber-like particles that are connected by a softer rubber network. Instead of relying on a single structure, the material uses these two interconnected networks to share mechanical forces.
When the material is stretched, the stress spreads across both networks instead of concentrating in one place. Much of the force is transferred into the softer regions between the tiny particles. There, long polymer chains can repeatedly slide and rearrange themselves, absorbing energy without permanently breaking the chemical bonds that hold the material together.
This means the material can endure repeated stretching and bending while remaining strong over time.
The granular structure also helps prevent cracks from spreading quickly. In many materials, cracks travel in a straight line, allowing damage to grow rapidly until the material fails. In the new elastomer, however, cracks are forced to weave around the microscopic particles through softer regions. This winding path slows the growth of cracks and makes the material much more resistant to failure.
Laboratory tests showed impressive results. The optimized DNGEs were up to 15 times more resistant to fracture than comparable soft materials and up to three times better at withstanding repeated mechanical stress without developing fatigue damage.
These properties make the material especially attractive for technologies that must flex, stretch and bend repeatedly over long periods. Potential applications include soft robotic systems, flexible electronic devices, wearable sensors, medical implants and other biomedical technologies where durability is essential.
The research team is already working to make the material even more environmentally friendly. They are exploring the use of biodegradable elastomers as well as materials made from recycled sources, with the goal of reducing environmental impact while maintaining the material’s excellent mechanical performance.
The researchers hope their approach will make advanced soft materials more widely available. Because DNGEs are designed to work with commercial 3D printers, laboratories and manufacturers could eventually produce custom-made, high-performance components without requiring specialized equipment.
The discovery demonstrates that a material originally designed to improve 3D printing may also provide a new blueprint for creating stronger, longer-lasting flexible materials for a wide range of future technologies.
