|Scientists from the Max Planck Institute for Intelligent Systems in
Germany have unveiled spherical microbots capable of propelling
themselves through water and killing off bacteria at the same time,
potentially giving us a new and effective way of tackling contaminated
Swimming through water infected with E. coli, the new bots were able to
kill more than 80% of the bacteria present inside 20 minutes, and
because they're magnetic they can be easily pulled from the water too.
That is a big advantage over adding cleaning chemicals to water,
chemicals which stick around after use and may not be very effective.
The bots are divided in two - one half is made of magnesium, which
creates hydrogen bubbles in water and acts as a propulsion system. The
other half is made of alternating iron and gold layers topped off with
silver nanoparticles, and acts as the bacteria-blasting part of the mini
machine. The iron and gold layers trap the target bacteria, and the
nanoparticles kill them off.
It's the iron that enables magnets to draw out the microbots after
they've done their cleaning duties, along with the trapped, dead
bacteria, because you don't really want to be drinking or swimming
around in water that's packed with microbots. The more bots that get
added, the more effective the cleaning is likely to be.