- Tiny robots actively hunt nanoplastics instead of waiting for contact
- Electrostatic attraction allows nanobots to grasp charged plastic-like surfaces
- Magnetic control allows precise movement without fuel or light
There is a lot of plastic waste in the world, putting the environment at risk, and tiny particles of these plastics are now contaminating drinking water.
These particles, called nanoplastics, are so small that they can pass through conventional water filters, enter human organs and cause diseases such as cancer.
Researchers at Brno University of Technology have developed a small magnetic robot that can search for and remove these tiny particles from water.
Article continues below
How little robots capture plastic particles
The research, published in Environmental Sciences: Nanofound that these nanorobots use electrostatic attraction to remove nanoplastics in the same way a balloon clings to your hair.
“What stands out is how these robots are designed to attract plastics using electrostatics,” said Sylvain Martel, a computer engineer who was not involved in the work.
The robots come with hexagonal rods formed from iron-based organometallic structures, and each rod is about the width of a human hair.
Under a scanning electron microscope, each rod looks like a cratered meteorite, with pores that become sites for nanoplastics to cling to.
These rods were then heated, causing them to rearrange into magnetic compounds, allowing the robots’ movement to be externally controlled by magnets.
These robots operate using low-energy magnetic fields and require no additives, making them more efficient than models using fuels or ultraviolet light.
After extracting the plastic, a simple magnet is used to attract the robots to the glass wall so that the cleaned water can be drained away.
Previous efforts to clean plastic using nanobots relied on passive capture, simply placing the robots in water and waiting for the nanoplastics to drift close enough to stick.
The new study reverses this approach by sending robots to actively search for particles.
“If it’s just particles hoping to attract the nanoplastic, we don’t call it a robot,” said Martin Pumera, the lead researcher. “The idea is the active matter.”
In laboratory tests, moving robots captured 78% of particles after an hour, about 60% more than when the robots were completely still.
Real-world limitations
As robots are used to clean water, they degenerate, which is one of the challenges of this technology.
Although an acid bath can regenerate robots, their performance declines after four cycles of reuse as the pores become clogged.
When tested in simulated seawater and groundwater, the robots’ efficiency dropped by about 70% because the dissolved ions competed with the nanoplastics for the robots’ electrostatic attraction.
Since robots only move a few micrometers per second and magnetic fields decrease rapidly with distance, scaling them is a challenge.
Conventional factories process millions of gallons per day, but these robots crawl so slowly that it would take an inconvenient amount of time to clean even a tiny fraction of that volume.
The dramatic decline in saltwater and groundwater efficiency also raises questions about real-world viability.
As exciting as this technology may seem, it is most likely a clever laboratory demonstration rather than a scalable solution to the growing crisis of nanoplastic contamination in drinking water.
Follow TechRadar on Google News And add us as your favorite source to get our news, reviews and expert opinions in your feeds.
