Hydrogel

Hydrogel is a material that is like a sponge but it is made from very tiny pieces of plastic called polymers. It is special because it can soak up a lot of water - sometimes even up to 100 times its own weight. This makes it really useful for things like keeping plants watered in the garden and in medical settings too. By soaking up the water, it helps to keep whatever it touches cool and moist, which is really important for keeping things healthy.