Super gel
A team of experts in mechanics, materials science, and tissue engineering at Harvard has created an extremely stretchy and tough gel that may suggest a new method for replacing damaged cartilage in human joints. The new material, a hydrogel, is a strong hybrid of two weak gels. Not only can it stretch to 21 times its original length, but it is also tough, self-healing, and biocompatible — attributes that open up new opportunities in medicine and tissue engineering. The material, its properties, and a simple method of synthesis are described in the Sept. 6 issue of Nature. “Conventional hydrogels are very weak and brittle — imagine a spoon breaking through jelly,” said lead author Jeong-Yun Sun, a postdoctoral fellow at the Harvard School of Engineering and Applied Sciences (SEAS). “But because [these gels] are water-based and biocompatible, people would like to use them for some very challenging applications like artificial cartilage or spinal...