Researchers have developed self-healing rubber, which is intended for light 3D printing and can have different stiffery levels.
Everyone came across problems due to a tire or cracked soles in shoes, after which they become unfit for future use. A team from Southern California University of Southern California Engineering School has developed a 3D-printed rubber material that can independently restore its structure.
The production technology is based on photopolymerization — the process of hardening the liquid resin under the action of light achieved through the use of thiols. When the oxidizing agent is added to a chemical mixture, thiols turn into disulfides, a group of chemicals that are capable of self-healing.
However, an increase in the stake of the oxidant leads not only to improve the «healing», but also to the weakening of photopolymerization. Therefore, researchers stopped on an optimal ratio, which provides operational splicing and fairly rapid solidification. As a result, the printing of the square with the sides of 17.5 mm takes only 5 seconds, and about 20 minutes leaves for the manufacture of whole products.
The recovery rate on average lasts a few hours and depends on the temperature of the material. The optimal conditions are the range from 40 ° C to 60 ° C, while the structure can be restored almost 100%. At room temperature, the process also flows, but requires more time.
Researchers used the developed technology to create a shoe sole, an element of soft robotics, a multiphase composite and an electronic sensor. At the moment they are studying ways to change the levels of stiffness of the material to expand its scope.
Previously, we also reported that scientists from nine research institutes created extremely light