Microbots capable of cleaning radioactive wasteMarie Donlon | November 01, 2019
In an effort to clean up the radioactive isotopes left behind by nuclear power plants — either following a spill or as runoff in wastewater — a team of scientists from the University of Chemistry and Technology, Prague, in the Czech Republic has developed self-propelled microbots that are capable of removing radioactive uranium.
While scientists have already developed materials capable of capturing, separating, recovering and removing radioactive uranium from water, the team from Prague has instead turned to metal organic frameworks (MOFs), which are porous compounds capable of trapping certain substances, including radioactive uranium. The team, led by researcher Martin Pumera, outfitted a rod-shaped MOF, dubbed ZIF-8, with a micromotor for rapidly capturing and removing radioactive waste.
The ZIF-8 is 1/15 the diameter of a strand of human hair and contains both iron atoms and iron oxide nanoparticles to stabilize and magnetize the rods. Additionally, catalytic platinum nanoparticles were added to one end of each of the MOF rods. There, the nanoparticles converted hydrogen peroxide “fuel” and transformed it into an oxygen bubble that thrust the MOF microbots at speeds of roughly 60 times their length per second.
Placed in simulated radioactive wastewater, the microbots reportedly captured an estimated 96% of uranium in one hour. Once captured, the MOF rods were gathered by a magnet and divested of the uranium, leaving the microbots appropriate for reuse.
This development, according to researchers, could pave the way for nuclear power to meet the world’s energy demands without the byproduct of greenhouse gases or the potential to contaminate water and thus humans and wildlife. Likewise, the microbots could help in the aftermath of another nuclear plant disaster in the vein of Chernobyl or Fukushima.
The MOF microbots are just one example of a growing trend of robots taking on tasks and jobs too dangerous for humans to undertake. Some examples of this include the United States Navy successfully testing an autonomous, robotic system that detects, identifies and destroys sea mines. This is in addition to the many security robots reportedly cropping up at airports and hospitals around the world.
The research appears in the journal ACS Nano.