Scientists in the Czech Republic have developed microrobots that move using magnetic fields to capture microplastics from water and soil. Microplastics are among the most difficult pollutants to extract once they spread into natural environments.
The devices are manufactured from MXenes, which are two-dimensional materials with extremely thin layers, combined with magnetic nickel nanoparticles. When an external rotating magnetic field is applied, the microrobots move through contaminated material without needing conventional motors, batteries, or electronic components.
As they travel, the surface of each device contacts plastic fragments and retains them. Unlike traditional filters that wait for pollutants to float by, these microrobots actively swim toward the contaminants.
Laboratory testing showed that cleanup performance varies depending on the polymer type and the environment. In water tests lasting about one hour, the system removed up to 94 percent of polystyrene and 89 percent of polyethylene terephthalate, also known as PET.
Soil performance and field challenges
In soil samples, where plastic particles remain trapped between minerals and organic matter, the microrobots circulated through tiny water-filled spaces to reach the pollutants. Under those experimental conditions, the system extracted about 81 percent of polystyrene and 72 percent of PET.
Researchers noted that a major gap remains between controlled lab tests and large-scale environmental use. Real rivers, wetlands, and agricultural soils contain clays, microorganisms, and organic matter that could alter how the devices behave.
Retrieving the microrobots after cleanup presents another key challenge because the devices contain nickel and nanoscale materials. Scientists must evaluate their toxicity, stability, reusability, and full magnetic retrieval before deploying the system outside the laboratory.
