Micro- and nanoplastic pollution is pervasive worldwide, infiltrating drinking water and food chains, accumulating in the human body, and posing serious threats to public health and ecosystems. Despite these urgent challenges, effective strategies to curb the widespread presence of micro- and nanoplastics have not yet been sufficiently developed. Here, we present magnetically driven living bacterial microrobots that exhibit a nature-inspired three-dimensional (3D) swarming motion, allowing the dynamic capture and retrieval of aquatic micro- and nanoplastics originating from various commercial products. By combining autonomous propulsion with magnetically guided navigation, we enabled the multimodal swarming manipulation of magnetotactic bacteria-based living microrobots (MTB biobots). The actuation of a rotating magnetic field induces a fish schooling-like 3D swarming navigation, allowing the active capture of micro- and nanoplastics, which are then retrieved from the contaminated water by magnetic separation. Our results show that the 3D magnetic swarming of MTB biobots synergistically enhances the removal efficiencies of both model and real-world microplastics, demonstrating their practical potential in water treatment technologies. Overall, plastic-seeking living bacterial microrobots and their swarm manipulation offer a straightforward and environmentally friendly approach to micro- and nanoplastic treatment, providing a biomachinery-based solution to mitigate the pressing microplastic pollution crisis.

• Keywords
• biohybrid microrobots, magnetically driven, magnetotactic bacteria, microplastics, nanoplastics, swarming behavior, water purification,
• MeSH
• Water Pollutants, Chemical * isolation & purification   chemistry   MeSH
• Water Purification * methods   MeSH
• Magnetic Fields MeSH
• Microplastics * isolation & purification   chemistry   MeSH
• Robotics * MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Water Pollutants, Chemical * MeSH
• Microplastics * MeSH

Inspired by Richard Feynman's 1959 lecture and the 1966 film Fantastic Voyage, the field of micro/nanorobots has evolved from science fiction to reality, with significant advancements in biomedical and environmental applications. Despite the rapid progress, the deployment of functional micro/nanorobots remains limited. This review of the technology roadmap identifies key challenges hindering their widespread use, focusing on propulsion mechanisms, fundamental theoretical aspects, collective behavior, material design, and embodied intelligence. We explore the current state of micro/nanorobot technology, with an emphasis on applications in biomedicine, environmental remediation, analytical sensing, and other industrial technological aspects. Additionally, we analyze issues related to scaling up production, commercialization, and regulatory frameworks that are crucial for transitioning from research to practical applications. We also emphasize the need for interdisciplinary collaboration to address both technical and nontechnical challenges, such as sustainability, ethics, and business considerations. Finally, we propose a roadmap for future research to accelerate the development of micro/nanorobots, positioning them as essential tools for addressing grand challenges and enhancing the quality of life.

• Keywords
• collective behavior, functionality, intelligence, micro/nanorobots, nanotechnology, propulsion, smart materials, technological translation,
• MeSH
• Humans MeSH
• Nanotechnology * methods   MeSH
• Robotics * instrumentation   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Review MeSH

Nanoplastics are considered an emerging organic persistent pollutant with possible severe long-term implications for the environment and human health; therefore, their remediation is of paramount importance. However, detecting and determining the concentration of nanoparticles in water is challenging and time-consuming due to their small size. In this work, we present a universal yet simple method for the detection and quantification of nanoplastics to monitor their removal from water using magnetic nanorobots. Nanoplastics were stained with a hydrophobic fluorescent dye to enable the use of photoluminescence techniques for their detection and quantification. Magnetic nanorobotic tools were employed to capture and subsequently remove the nanoplastics from contaminated waters. We demonstrated that nanorobots can capture and remove more than 90% of the nanoplastics from an aqueous solution within 120 min. This work shows that easy-to-use common fluorescent dyes combined with photoluminescence spectroscopy methods can be used as an alternative method for the detection and quantification of nanoplastics in water environments and swarming magnetic nanorobots for efficient capture and removal. These methods hold great potential for future research to improve the quantification and removal of nanoplastics in water, and it will ultimately reduce their harmful impact on the environment and human health.

• Publication type
• Journal Article MeSH

The brewing industry will amass a revenue above 500 billion euros in 2022, and the market is expected to grow annually. This industrial process is based on a slow sugar fermentation by yeast (commonly Saccharomyces cerevisiae). Herein, we encapsulate yeast cells into a biocompatible alginate (ALG) polymer along Fe3O4 nanoparticles to produce magneto/catalytic nanostructured ALG@yeast-Fe3O4 BioBots. Yeast encapsulated in these biocompatible BioBots keeps their biological activity (growth, reproduction, and catalytic fermentation) essential for brewing. Catalytic fermentation of sugars into CO2 gas caused a continuous oscillatory motion of the BioBots in the solution. This BioBot motion is employed to enhance the beer fermentation process compared to static-free yeast cells. When the process is finished, magnetic actuation of BioBots is employed for their retrieval from the beer samples, which avoids the need of additional filtration steps. All in all, we demonstrate how an industrial process such as beer production can be benefited by miniaturized autonomous magneto/catalytic BioBots.

• Keywords
• beer, biohybrid, brewing, driven, fermentation, hydrogel, magnetic, robots,
• MeSH
• Fermentation MeSH
• Beer * analysis   MeSH
• Saccharomyces cerevisiae * MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

The recent COVID-19 pandemic has resulted in the massive discard of pandemic-related plastic wastes, causing serious ecological harm and a high societal burden. Most single-use face masks are made of synthetic plastics, thus their careless disposal poses a direct threat to wildlife as well as potential ecotoxicological effects in the form of microplastics. Here, we introduce a 1D magnetic photoactive microswarm capable of actively navigating, adhering to, and accelerating the degradation of the polypropylene microfiber of COVID-19 face masks. 1D microrobots comprise an anisotropic magnetic core (Fe3O4) and photocatalytic shell (Bi2O3/Ag), which enable wireless magnetic maneuvering and visible-light photocatalysis. The actuation of a programmed rotating magnetic field triggers a fish schooling-like 1D microswarm that allows active interfacial interactions with the microfiber network. The follow-up light illumination accelerates the disruption of the polypropylene microfiber through the photo-oxidative process as corroborated by morphological, compositional, and structural analyses. The active magnetic photocatalyst microswarm suggests an intriguing microrobotic solution to treat various plastic wastes and other environmental pollutants.

• MeSH
• COVID-19 * prevention & control   MeSH
• Humans MeSH
• Masks * MeSH
• Pandemics prevention & control   MeSH
• Plastics MeSH
• Polypropylenes MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Plastics MeSH
• Polypropylenes MeSH

Hybrid biological robots (biobots) prepared from living cells are at the forefront of micro-/nanomotor research due to their biocompatibility and versatility toward multiple applications. However, their precise maneuverability is essential for practical applications. Magnetotactic bacteria are hybrid biobots that produce magnetosome magnetite crystals, which are more stable than synthesized magnetite and can orient along the direction of earth's magnetic field. Herein, we used Magnetospirillum magneticum strain AMB-1 (M. magneticum AMB-1) for the effective removal of chlorpyrifos (an organophosphate pesticide) in various aqueous solutions by naturally binding with organic matter. Precision control of M. magneticum AMB-1 was achieved by applying a magnetic field. Under a programed clockwise magnetic field, M. magneticum AMB-1 exhibit swarm behavior and move in a circular direction. Consequently, we foresee that M. magneticum AMB-1 can be applied in various environments to remove and retrieve pollutants by directional control magnetic actuation.

• Keywords
• magnetic actuation, magnetotactic bacteria, micromotors, microrobots, nanorobots,
• MeSH
• Bacteria metabolism   MeSH
• Bacterial Proteins metabolism   MeSH
• Decontamination MeSH
• Magnetospirillum * metabolism   MeSH
• Ferrosoferric Oxide * MeSH
• Robotics methods   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Bacterial Proteins MeSH
• Ferrosoferric Oxide * MeSH

Less than 1% of Earth's freshwater reserves is accessible. Industrialization, population growth and climate change are further exacerbating clean water shortage. Current water-remediation treatments fail to remove most pollutants completely or release toxic by-products into the environment. The use of self-propelled programmable micro- and nanoscale synthetic robots is a promising alternative way to improve water monitoring and remediation by overcoming diffusion-limited reactions and promoting interactions with target pollutants, including nano- and microplastics, persistent organic pollutants, heavy metals, oils and pathogenic microorganisms. This Review introduces the evolution of passive micro- and nanomaterials through active micro- and nanomotors and into advanced intelligent micro- and nanorobots in terms of motion ability, multifunctionality, adaptive response, swarming and mutual communication. After describing removal and degradation strategies, we present the most relevant improvements in water treatment, highlighting the design aspects necessary to improve remediation efficiency for specific contaminants. Finally, open challenges and future directions are discussed for the real-world application of smart micro- and nanorobots.

• Keywords
• Molecular machines and motors,
• Publication type
• Journal Article MeSH
• Review MeSH

Nanoplastic pollution, the final product of plastic waste fragmentation in the environment, represents an increasing concern for the scientific community due to the easier diffusion and higher hazard associated with their small sizes. Therefore, there is a pressing demand for effective strategies to quantify and remove nanoplastics in wastewater. This work presents the "on-the-fly" capture of nanoplastics in the three-dimensional (3D) space by multifunctional MXene-derived oxide microrobots and their further detection. A thermal annealing process is used to convert Ti3C2Tx MXene into photocatalytic multi-layered TiO2, followed by the deposition of a Pt layer and the decoration with magnetic γ-Fe2O3 nanoparticles. The MXene-derived γ-Fe2O3/Pt/TiO2 microrobots show negative photogravitaxis, resulting in a powerful fuel-free motion with six degrees of freedom under light irradiation. Owing to the unique combination of self-propulsion and programmable Zeta potential, the microrobots can quickly attract and trap nanoplastics on their surface, including the slits between multi-layer stacks, allowing their magnetic collection. Utilized as self-motile preconcentration platforms, they enable nanoplastics' electrochemical detection using low-cost and portable electrodes. This proof-of-concept study paves the way toward the "on-site" screening of nanoplastics in water and its successive remediation.

• MeSH
• Microplastics * MeSH
• Nanoparticles * MeSH
• Wastewater MeSH
• Oxides MeSH
• Plastics MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Microplastics * MeSH
• Waste Water MeSH
• Oxides MeSH
• Plastics MeSH

The increasing accumulation of persistent nondegradable microplastics in the marine environment represents a global environmental problem. Among emerging approaches to tackle microplastics are micro- and nanomotors, tiny devices capable of autonomous propulsion powered by chemical fuels or light. These devices are capable of on-the-fly recognition, capture, and decomposition of pollutants. In the past, various micromotors were designed to efficiently remove and degrade soluble organic pollutants. Current effort is given to the rational design and surface functionalization to achieve micromotors capable of capturing, transporting, and releasing microplastics of different shapes and chemical structures. The catalytic micromotors performing photocatalysis and photo-Fenton chemistry hold great promise for the degradation of most common plastics. In this review, we highlight recent progress in the field of micromotors for microplastics treatment. These tiny self-propelled machines are expected to stimulate a quantum leap in environmental remediation.

• Publication type
• Journal Article MeSH
• Review MeSH