Hydrogel is mostly water, but strong as silicone rubber

I am always on the lookout for cool cutting-edge chemistry for my Make: Projects series. It doesn’t happen often, but occasionally there’s a breakthrough that’s both interesting and important, and yet easy enough that even non-professionals can replicate it in their kitchens. It’s one of my dreams to someday present a home chemistry project based on science just published, within the preceding week, in one of the major journals.


This, unfortunately, isn’t it. But it’s dang close.

You’re looking at a piece of hydrogel. It is 98% water by weight. It’s moldable, transparent, environmentally friendly, easily synthesized and (get this) if it’s cut it will heal itself. Its creator, Takuzo Aida at the University of Tokyo, has compared it to silicone rubber in terms of strength. And to make it, all you have to do is stir three ingredients into a bunch of water at room temperature. These are sodium polyacrylate, clay, and a special dendritic molecule Aida and co-workers call “G3 binder.”

It’s that last ingredient that gums it up, if you’ll pardon the expression, for home enthusiasts. Unlike the other ingredients, you can’t just order a bottle of Aida’s G3 dendrimer off the web and play along at home. And, per the supporting information for Aida’s recent Nature paper, the synthesis of G3 is actually pretty hairy.

Too bad. Maybe next time. Still, it’s awesome chemistry.


I am descended from 5,000 generations of tool-using primates. Also, I went to college and stuff. I am a long-time contributor to MAKE magazine and My work has also appeared in ReadyMade, c't – Magazin für Computertechnik, and The Wall Street Journal.

View more articles by Sean Michael Ragan