SILVER MICRO-BOTS: For Life’s Most Essential Ingredient

This ain’t grandma plunking a Morgan Dollar into the milk jug. That’s too old-school. This is cutting-age tech that’s all about health and safety. Yet again: SILVER TO THE RESCUE!

From the Silver Institute

Silver-Based ‘Microbots’ Zap Bacteria in Water Supply

Like the classic video game where Pac-Man gobbles up colored dots, scientists at the Max-Planck Institute for Intelligent Systems in Stuttgart, Germany and the Institute for Bioengineering of Catalonia (IBEC) in Barcelona, have developed ‘microbots,’ tiny waterborne robots that attack lifethreatening bacteria as they swim through a contaminated water supply.

These self-propelled ‘Janus microbots’ — named for the Roman god usually depicted as having two faces — are composed of two spherical layers.

One face is made from magnesium, which, when dropped in water, produces hydrogen bubbles that propel the microbots. The other face is made from iron and gold layers coated with silver nanoparticles. As the microbots swim through the water, bacteria tend to stick to the gold and are killed by the nanosilver. Experiments have shown that the microbots can move through the water for about 15 to 20 minutes before the magnesium is used up and the hydrogen propulsion system is spent.



After the microbots have done their job, they are removed by sweeping a magnet through the water which attracts the iron in them.

Tests have shown that the system killed more than 80% of E. coli bacteria which was introduced into water at high concentrations. Adding more microbots would increase the kill rate, researchers say, without leaving behind any chemical contaminants.

“The use of conventional disinfectants produces harmful byproducts, and some pathogens have developed resistance to them, thereby exiting an urgent need to develop more effective, innovative, low-cost, robust, and safe water-cleaning methods,” the team wrote in their report. “We have demonstrated that Janus microbots decorated with AgNPs [silver nanoparticles] are an efficient bactericidal tool for water disinfection.”

The research was reported in the journal ACS Applied Materials & Interfaces.