Researchers develop magnetic algae microrobots to remove microplastics from aquatic environments

30 Oct 2023 --- Researchers at Central European Institute of Technology at Brno University of Technology, Czech Republic, have developed a novel solution to remove micro and nanoplastics from the aquatic environment. By integrating microalgae platforms with magnetic nanoparticles, they have created biohybrid microrobots, known as “magnetic algae robots” (MARs).

Chlorella vulgaris, a widely used microalgae in various biotechnology applications, serves as the structural platform for these microbots. By adorning the surface of the algae cells with Fe3O4 (magnetic oxide) nanoparticles, the team achieved MARs that respond to wireless magnetic manipulation, offering a rapid and precise on/off response to the magnetic field without the need for chemical fuels or costly metals. 

“Taking advantage of their active motion, MARs exhibited considerable efficiencies of 92% for nanoplastics and 70% for microplastics. The reusability of MARs was also tested over five cycles, preserving ≈80% removal efficiency for nanoplastics and approximately 54% for microplastics,” inform the researchers.

Furthermore, the nanoparticles had a hormesis effect on algae growth rather than posing higher toxicity concerns.

The MARs boast active movement and effective electrostatic interactions. In a series of experiments, the researchers demonstrated that MARs are exceptionally efficient at capturing nanoplastics, outperforming their performance with microplastics. 

One notable feature of these magnetic microrobots highlighted by the researchers is their adaptability to different aquatic environments, enhancing their practicality and rendering them promising candidates for real-world applications.

Biohybrid MARs for effective removal of micro and nanoplastics from water (Image credit: X. Peng et. al).The study was published in the Advanced Functional Materials journal.

Cost-effective and efficient
The creation of these biohybrid MARs offers a sustainable, cost-effective and efficient method for the capture and removal of micro and nanoplastics from aquatic environments. 

Micro and nanoplastics, tiny fragments resulting from the degradation of larger plastic waste, pose a substantial threat to aquatic life and human health. 

According to the researchers, traditional removal methods have proven inadequate, especially when dealing with tiny plastic fragments. This has necessitated the urgent development of efficient and reliable strategies to mitigate the risks associated with micro and nanoplastics.

Embracing sustainability, the MARs offer a low-cost and eco-friendly solution, aligning with the growing consumer awareness and policy crackdown on climate change.

“In conclusion, we have presented eco-friendly and magnetic field-driven algae-based microrobots for effective capture and removal of micro/nanoplastics from the aquatic environment,” write the researchers. 

“The introduced biohybrid microrobots, originating from naturally existing microalgae integrated with magnetic Fe3O4 nanoparticles, hold considerable promise for addressing environmental challenges associated with micro and nanoplastics sustainably and cost-effectively.”

Edited by Radhika Sikaria