On-the-Fly Monitoring of the Capture and Removal of Nanoplastics with Nanorobots

Innovative materials that behave like robots to combat plastic pollution

The growing plastic pollution crisis demands novel approaches, with innovative materials that mimic robotic behaviors emerging as a promising solution. This approach explores the development and application of smart materials that can autonomously engage in plastic waste removal, functioning like robots under various environmental conditions. We focus on materials activated by light, magnetic fields, chemical fuels, and ion exchange, which are designed to target and remove plastic waste efficiently. The key properties of these materials, such as self-activation, adaptability, and precision that enable them to function autonomously in waste management systems, are examined. The integration of these innovative materials offers significant advantages, including faster waste processing, reduced human exposure to hazardous waste, and enhanced sorting accuracy. Additionally, this review evaluates the environmental impact, scalability, and cost-effectiveness of these materials in comparison to traditional methods. Finally, the potential of these materials to play a central role in sustainable plastic waste management and contribute to a circular economy is discussed.

Machine learning-driven optical microfiltration device for improved nanoplastic sampling and detection in water systems

The rising presence of nanoplastics in water poses toxicity risks and long-term ecological and health impacts. Detecting nanoplastics remains challenging due to their small size, complex chemistry, and environmental interference. Traditional filtration combined with Raman spectroscopy is time-consuming, labor-intensive, and often lacks accuracy and sensitivity. This study presents an agarose-based microfiltration device integrated with machine learning-assisted Raman analysis for nanoplastic capture and identification. The 1 % agarose microfluidic channel features circular micropost arrays enabling dual filtration: nanoplastics diffuse into the porous matrix, while larger particles (>1000 nm) are blocked by the microposts. Unlike conventional systems, this design achieves both physical separation and preconcentration, enhancing nanoplastic detectability. Upon dehydration, the agarose forms a transparent film, significantly improving Raman compatibility by minimizing background interference. This transformation enables direct Raman analysis of retained nanoparticles with enhanced signal clarity and sensitivity. Using 100-nm polystyrene nanoparticles (PSNPs) as a model, we evaluated device performance in distilled water and seawater across concentrations (6.25-50 µg/mL) and flow rates (2.5-100 µL/min). Maximum capture efficiencies of 80 % (seawater) and 66 % (distilled water) were achieved at 2.5 µL/min. A convolutional neural network (CNN) further enhanced spectral analysis, reducing mapping time by 50 % and enabling PSNP detection in seawater at 6.25 µg/mL. This agarose-based system offers a scalable, cost-effective platform for nanoplastic sampling, demonstrating the potential of combining microfluidics with machine learning-assisted Raman spectroscopy to address critical environmental and public health challenges.

Nano-/Microrobots for Environmental Remediation in the Eyes of Nanoarchitectonics: Toward Engineering on a Single-Atomic Scale

Nano-/microrobots have been demonstrated as an efficient solution for environmental remediation. Their strength lies in their propulsion abilities that allow active "on-the-fly" operation, such as pollutant detection, capture, transport, degradation, and disruption. Another advantage is their versatility, which allows the engineering of highly functional solutions for a specific application. However, the latter advantage can bring complexity to applications; versatility in dimensionality, morphology, materials, surface decorations, and other modifications has a crucial effect on the resulting propulsion abilities, compatibility with the environment, and overall functionality. Synergy between morphology, materials, and surface decorations and its projection to the overall functionality is the object of nanoarchitectonics. Here, we scrutinize the engineering of nano-/microrobots with the eyes of nanoarchitectonics: we list general concepts that help to assess the synergy and limitations of individual procedures in the fabrication processes and their projection to the operation at the macroscale. The nanoarchitectonics of nano-/microrobots is approached from microscopic level, focusing on the dimensionality and morphology, through the nanoscopic level, evaluating the influence of the decoration with nanoparticles and quantum dots, and moving to the decorations on molecular and single-atomic level to allow very fine tuning of the resulting functionality. The presented review aims to lay general concepts and provide an overview of the engineering of functional advanced nano-/microrobot for environmental remediation procedures and beyond.

Are micro/nanorobots an effective solution to eliminate micro/nanoplastics in water/wastewater treatment plants?

The extensive production and widespread use of plastic products have resulted in the gradual escalation of plastic pollution. Micro/nano/plastic pollution has become a global issue, and addressing how to "green" remove them is a crucial topic that needs to be tackled at this stage. Recently, micro/nanorobots have offered a promising solution for improving water monitoring and remediation as an environmentally friendly remediation strategy. Micro/nanorobots have been proven to efficiently remove micro/nanoplastics from water bodies. Micro/nanoplastics are captured by micro/nanorobots in water through electrostatic adsorption and electrophoretic interactions, and separation is achieved under the action of an external transverse rotating magnetic field. Their small size enables them to navigate easily in complex environments, while magnetic and optical drives help them move along established routes and reach different areas. With the assistance of these innovative robots, diffusion-limited reactions can be overcome, allowing for active contact with target pollutants. However, research on the removal of micro/nanoplastics by micro/nanorobots is still in its early stages. The dependence on chemical fuels and high costs severely limit the development and application of micro/nanorobots. Micro/nanoplastics are frequently captured by micro/nanorobots, but the degradation efficiency of micro/nanoplastics remains very low. Additionally, the secondary pollution caused by micro/nanorobots is also a key factor limiting their implementation. Although micro/nanorobots are a very promising technology for removing micro/nanoplastics, they still need to be explored in their applications. This paper discusses the opportunities and challenges faced by micro/nanorobots in removing micro/nanoplastics. Development and application of self-driven intelligent micro/nanorobots will help expedite the eco-friendly removal of micro/nanoplastics and other emerging pollutants.