Researchers have developed a family of elastomers that they believe are the most elastic to date and can be fabricated using 3D-printing technologies, making these useful materials more accessible for a range of applications from soft robots to flexible electronics.
A team of engineers from Singapore University of Technology and Design's (SUTD) Digital Manufacturing and Design (DManD) Centre developed the materials, which are believed to be the most stretchable elastomers invented so far, with the ability to stretch by up to 1100 percent, they said.
Moreover, and perhaps more importantly, the materials are suitable for UV-curing-based 3D-printing techniques, which solidify liquid polymer resins to 3D objects through patterned UV light to fabricate elastomeric 3D objects. Previously, most of the commercially available UV-curable 3D-printable elastomers would break at less than 200-percent elasticity, making them unsuitable for many applications, researchers said.
"We have developed the most stretchable 3D printable elastomer in the world," said Qi Ge, an assistant professor at the SUTD's DManD Centre, and a co-leader of the project. "Our new elastomers can be stretched by up to 1100 percent, which is more than five times the elongation at break of any commercially available elastomer that is suitable for UV-curing-based 3D-printing techniques."
Researchers in Singapore have developed a family of elastomers that they believe are the most stretchable to date, with the ability to stretch by up to 1100 percent. They tested the materials suitability for flexible electronics in a 3D-printed conductive buckyball electric switch, pictured here. (Source: Dinesh K. Patel)
Ge and his co-collaborators published a paper on their research in the Journal of Advanced Materials .
Elastomers can be used in a number of applications because of their elasticity, resilience, and electrical and thermal insulation. Soft robots, flexible electronics, and next-generation biomedical devices that require soft, flexible material for appropriate and safe patient interaction are among some of the uses for these materials.
However, until now, the most commonly used silicon rubber-based elastomers required a thermal curing process that significantly limits their fabrication, constraining design freedom and geometric complexity.
Ge and his team were able to circumvent traditional difficulties in the fabrication of highly stretchable elastomers by using high-resolution 3D printing with their elastomer compositions. This enabled the direct creation of complex 3D lattices or hollow structures that exhibited extremely large deformation, he said.
"The new elastomers enable us to directly print complicated geometric structures and devices--such as a 3D soft robotic gripper--within an hour,” Ge said.
Indeed, the ability to use UV-curing-based 3D printing with the new elastomers—as opposed to the “complicated and time-consuming fabrication steps such as mold-building, molding/demolding”—can reduce the fabrication time of elastomer parts from “many hours or even days” to a few minutes or hours in a single 3D-printing step, he said.
The team tested the material’s ability not only to sustain large elastic deformation, but also maintain good mechanical repeatability in a 3D buckyball light switch that continued to work even after being pressed more than 1,000 times, Ge said. This shows the material’s viability for flexible electronics, as well as soft actuators and robots,