Innovative Ink for Flexible 3D Printing

Engineers working on soft robotics or wearable devices face the ongoing challenge of keeping their creations lightweight. Heavier materials not only require more energy to move around but can also lead to discomfort, especially in the case of wearables or prostheses. Elastomers, synthetic polymers with a range of mechanical properties from stiff to stretchy, have emerged as a popular material for such applications. However, the ability to manufacture elastomers that can be shaped into complex 3D structures transitioning from rigid to rubbery has been a longstanding obstacle.

Esther Amstad, head of the Soft Materials Laboratory in EPFL’s School of Engineering, explains the breakthrough: “Elastomers are usually cast in a way that limits their composition from being altered in all three dimensions over short length scales. To address this limitation, we have developed DNGEs: 3D-printable double network granular elastomers that offer an unprecedented degree of variability in their mechanical properties.”

One of the notable applications of this innovation was demonstrated by Eva Baur, a PhD student in Amstad’s lab, who used DNGEs to 3D print a prototype ‘finger’. This finger featured rigid ‘bones’ surrounded by flexible ‘flesh’ and was designed to deform in a pre-defined manner. This successful prototype showcases the technology’s potential to manufacture devices that are both supple enough to bend and stretch, yet firm enough to effectively manipulate objects.

The ability to create such intricate structures with varying mechanical properties opens up new possibilities in the fields of soft robotics and wearable devices. Researchers and engineers can now explore designs that were previously unattainable, leading to advancements in prosthetics, exoskeletons, and other applications requiring a delicate balance between flexibility and rigidity.

With DNGEs paving the way for customizable elastomers that can adapt their properties based on specific requirements, the future of soft robotics and wearable technology looks promising. This innovative approach not only enhances the performance of these devices but also improves user comfort and overall functionality. As further research and development continue in this area, we can expect to see even more groundbreaking applications and solutions emerging in the near future.