New 3D printing technique using silicone paste expands tech applications
The NCSU technique combines water with solid and liquid forms of silicone into a pasty ink that can be fed through a 3D printer.
Researchers at North Carolina State University have developed a new 3D printing technique that produces flexible and porous silicone rubber structures. The team used the principles behind the formation of sand castles built from wet sand and was able to come up with a technique that combines water with solid and liquid forms of silicone into a pasty ink that can be fed through a 3D printer.
The team was able to demonstrate that in a water medium, liquid silicone rubber can be used to form bridges between tiny silicone rubber beads to link them together. However, an interesting finding was that the technique can be used in a dry or wet environment.
The finding could have biomedical applications and uses in soft robotics. The team suggests it has the potential to be used in live tissue. For example, think of an ultraflexible mesh encapsulating a healing droplet, or a soft bandage that can be applied or even directly printed on some portion of the human body.
The finding could have biomedical applications and uses in soft robotics.
“There is great interest in 3-D printing of silicone rubber, or PDMS, which has a number of useful properties,” said Velev, INVISTA Professor of Chemical and Biomolecular Engineering at NC State. “The challenge is that you generally need to rapidly heat the material or use special chemistry to cure it, which can be technically complex.
The team’s method uses an extremely simple extrudable material that can be placed in a 3D printer to directly prototype porous, flexible structures – even under water, Velev added.
“And it is all accomplished with a multiphasic system of just two materials – no special chemistry or expensive machinery is necessary. The ‘trick’ is that both the beads and the liquid that binds them are silicone, and thus make a very cohesive, stretchable and bendable material after shaping and curing,” said Velev.
The paper is published in Advanced Materials. The paper is co-authored by first author Sangchul Roh, an NC State Ph.D. candidate; NC State graduate student Dishit Parekh; Bhuvnesh Bharti, a faculty member at Louisiana State University; and Dr. Simeon Stoyanov of Wageningen University in The Netherlands.
The research is funded by the National Science Foundation under grant CBET-1604116 and by the Research Triangle Materials Research Science and Engineering Center on Programmable Soft Matter under grant DMR-1121107. NC State has filed a provisional patent on the new technique.