Hydrogels have shown significant potential in everything from wound dressings to soft robots, but their applications have been limited from their lack of toughness – until now. A team of scientists at Hokkaido University have developed a new set of hydrogel composites or "fiber-reinforced soft composites" that combine hydrogels with woven fiber fabric to create a material that is five times stronger than carbon steel.
Composite materials have been around for millennia and the principle is very simple. A very soft substance like mud can be made strong enough to make bricks by adding straw as a tempering material. The same applies to adding crushed pottery to brick, seashells fragments to ceramic, or glass fiber to plastic.
The latter is very similar to the fiber-reinforced hydrogel. Hydrogels are made of hydrophilic polymer chains that absorb up to 90 percent water. They aren't very strong or durable, but by adding glass tiny fibers the researchers created a tough, bendable, stretchable material.
Scanning Electron Microscopy (SEM) images of the fiber-reinforced hydrogels (Credit: Hokkaido University)