Chemist Mingming Ma was working to make a plastic-like material for electrodes when he noticed his plastic was doing something strange. When he put a piece of it in his hand, it would curl up on itself and creep along his palm.
"I put it in my own hand and I found the polymer curved and it's, like, traveling in my hand," Ma told TechNewsDaily. "So I wanted to find out what's the reason, what's the mechanism of this movement?"
Ma soon learned that the moisture from his skin drove the material, a film made of two different kinds of polymers, or chemicals made of repeating units of the same molecule. Now, after further work with his colleagues in chemical engineer Robert Langer's laboratory at MIT, Ma has made small pieces of polymer material that continually curl, creep and leap when placed on a surface that's moister than the air. The researchers have also hooked the polymer pieces up to system that harvests tiny amounts of electricity from the polymer's movement.
Ray Baughman, a materials scientist at the University of Texas in Dallas who was not involved in Ma and Langer's work, called the polymer pieces "tiny robots" and noted they look alive as they move around on their own. "This is a very highly creative work by an MIT team that's known for its creativity," he said.
In the future, ingenious man-made materials like Ma and his colleagues' invention could power simple sensors that don't require much electricity, researchers say. Moisture-driven patches could also power small devices embedded in clothes, Ma thought. He had one interesting idea: Gym clothes with embedded heart rate monitors, powered by people's evaporating sweat.
Before gym-goers can put their sweat to good use, however, there's still plenty left for Ma left to do to improve his self-moving polymer. One major thing he'll be focusing on is making sure the polymer makes enough electricity to be useful.
I'm looking forward to see what uses this technology can encompass. It could be a way to utilize some recycled plastic if it is the right type of plastic.