Researchers have developed a tube-shaped microbot that offers a cheaper and more effective way of removing heavy metals than previous methods. The self-propelled microbots use an outer layer of graphene that binds to lead ions it comes in contact with. The scientists found that they can remove 95 percent of lead from polluted water in one hour, and once they have a full payload, they can be cleaned and reused multiple times.

Heavy metal pollutants, such as lead, cadmium, mercury and arsenic, are a persistent problem in industrial processes and their subsequent runoff. Besides battery and electronics manufacturing, mining and electroplating are especially guilty of generating hazardous levels of these toxic byproducts. The researchers have focused on lead removal initially as a proof-of-concept, since lead is a major waste water pollutant from the battery industry and others."These microbots could remove all contaminants that graphene can adsorb."