Swarms of Tiny Robots Remove Microplastics From Soil and Water

Scientists from the Czech Republic have developed microscopic cleanup robots capable of removing microplastics from both soil and water environments. The researchers began by utilizing microscopic MXene particles, which possess a large surface area and surface chemistry that enables them to attract and hold onto plastic. The particles were then coated with magnetic nickel nanoparticles, allowing external magnetic fields to control the tiny robots.

In a series of laboratory tests, the researchers placed swarms of these microbots into contaminated water and soil samples. The magnetic fields generated by the external source caused the robots to spin and tumble through the liquid, as well as navigate through the tiny water-filled gaps within the soil. Within these environments, the microrobots could actively disrupt microplastic entrapment within soil matrices and extract them.

As the microbots moved through the samples, their sticky surfaces would collide with microplastics, binding to them and dragging them along. Once the microbots had collected their cargo, a magnet could be used to pull them, along with the trapped plastic, out of the samples. The researchers found that the microbots performed exceptionally well.

In water, they managed to remove approximately 94% of polystyrene particles and 89% of PET (polyethylene terephthalate) within an hour. In the model soil, they extracted around 81% of polystyrene and 72% of PET.

This new method outperformed the same MXene material used without magnetic motion, which instead relied on passive adsorption rather than actively moving through soil and water.