Working out makes hydrogels perform more like muscle
Human skeletal muscles have a unique combination of properties that materials researchers seek for their own creations. They’re strong, soft, full of water, and resistant to fatigue. A new study by MIT researchers has found one way to give synthetic hydrogels this total package of characteristics: putting them through a vigorous workout. In particular, the scientists mechanically trained the hydrogels by stretching them in a water bath. And just as with skeletal muscles, the reps at the “gym” paid off. The training aligned nanofibers inside the hydrogels to produce a strong, soft, and hydrated material that resists breakdown or fatigue over thousands of repetitive movements. The polyvinyl alcohol (PVA) hydrogels trained in the experiment are well-known biomaterials that researchers use for medical implants, drug coatings, and other applications, says Xuanhe Zhao, an associate professor of mechanical engineering at MIT. “But one with these four important properties has not been designed or manufactured...