Additive manufacturing of self-healing elastomers

By Kunhao Yu, A. Xin, Haixu Du, Ying Li, Qiming Wang. NPG Asia Materials, 2019

141 citations recorded by the source corpus.

AbstractNature excels in both self-healing and 3D shaping; for example, self-healable human organs feature functional geometries and microstructures. However, tailoring man-made self-healing materials into complex structures faces substantial challenges. Here, we report a paradigm of photopolymerization-based additive manufacturing of self-healable elastomer structures with free-form architectures. The paradigm relies on a molecularly designed photoelastomer ink with both thiol and disulfide groups, where the former facilitates a thiol-ene photopolymerization during the additive manufacturing process and the latter enables a disulfide metathesis reaction during the self-healing process. We find that the competition between the thiol and disulfide groups governs the photocuring rate and self-healing efficiency of the photoelastomer. The self-healing behavior of the photoelastomer is understood with a theoretical model that agrees well with the experimental results. With projection microstereolithography systems, we demonstrate rapid additive manufacturing of single- and multimaterial self-healable structures for 3D soft actuators, multiphase composites, and architected electronics. Compatible with various photopolymerization-based additive manufacturing systems, the photoelastomer is expected to open promising avenues for fabricating structures where free-form architectures and efficient self-healing are both desirable.Polymers: Printable self-healing devicesA soft material that can heal itself when damaged has been 3D printed by researchers in the USA. Elastomers are elastic substances that can have the unusual ability to self-heal. This makes them potentially useful in robust flexible electronics, soft robotics and biomedical implants. However, all these applications require devices and structures to be three-dimensional. Qiming Wang and colleagues from the University of Southern California, Los Angeles, and colleagues have made such self-healing devices using a technology known as additive manufacturing, which creates three-dimensional objects by building them up layer by layer. The team were able to create a multiphase composite that can self-heal a fracture to return to 90% of its original toughness, and to build a three-dimensional soft robot that can lift ten times its own weight after healing a fatal fracture.A pathway for photopolymerization-based additive manufacturing of self-healable elastomer structures has been explored by Scientists in the United States.

Subfields: Biomedical Engineering, Mechanical Engineering, Polymers and Plastics

View Paper: https://www.semanticscholar.org/paper/9bac8297cff8156c565f64041db930c9725c2fa2