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

Ensuring food quality and safety according to stringent global standards requires analytical procedures that are accurate, cost-effective, and efficient. This present innovative high-throughput microrobots designed for the detection of antioxidants in food samples. These microrobots consist of photocatalytic bismuth subcarbonate anchored on silica-coated magnetite nanoparticles. Upon exposure to UV light, they generate reactive oxygen species via photocatalysis, which oxidize the colorless dye into a green-colored radical cation. The presence of antioxidants inhibits this reaction, allowing for the quantification of antioxidant activity. The magnetic Fe₃O₄/SiO₂ core enables steering of the microrobots using a transverse rotating magnetic field, facilitating automated assays on a custom-designed 3D-printed sensing platform. This results demonstrate that these magneto-photocatalytic microrobots can perform automated, high-throughput assessments of food quality, representing a significant advancement in food analysis technology.

• Keywords
• food analysis, microrobots, nanorobots,
• MeSH
• Food Analysis * methods   instrumentation   MeSH
• Antioxidants analysis   MeSH
• Food Quality * MeSH
• Magnetite Nanoparticles chemistry   MeSH
• Silicon Dioxide chemistry   MeSH
• Quality Control MeSH
• Robotics * instrumentation   MeSH
• High-Throughput Screening Assays * methods   instrumentation   MeSH
• Ultraviolet Rays MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Antioxidants MeSH
• Magnetite Nanoparticles MeSH
• Silicon Dioxide MeSH

Ammonia (NH₃) production is a critical industrial process, as ammonia is a key component in fertilizers, essential for global agriculture and food production. However, the current method of synthesizing ammonia, the Haber-Bosch process, is highly energy-intensive, and relies on fossil fuels, contributing substantially to greenhouse gas emissions. Moreover, the centralized nature of the Haber-Bosch process limits its accessibility in remote or resource-limited areas. Photochemical synthesis of ammonia, provides an alternate lower energy, carbon-free pathway compared to the prevailing industrial methods. The photoconversion of nitrate anions, often present in wastewater, offers a greener, more sustainable, and energy-efficient route for both ammonia-generation and wastewater treatment. Photochemical and chemical synthesis of ammonia requires intensive mass-transfer processes, which limits the efficiency of the method. To change the game, in this work, a key new technology of ammonia-generation, a catalytic ammonia generation (AmmoGen) microrobot, which converts nitrate to ammonia using renewable light energy is reported. The magnetic propulsion of the AmmoGen microrobots significantly enhances mass-transfer, and expedites the photosynthesis of ammonia. Overall, this "proof-of-concept" study demonstrates that microrobots can aid in catalytic small molecule activation and generation of value-added products; and are envisaged to pave the way toward new sustainable technologies for catalysis.

• Keywords
• ammonia, magnetically driven, microrobots, nitrate reduction, photosynthesis,
• Publication type
• Journal Article 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 forefront of micro- and nanorobot research involves the development of smart swimming micromachines emulating the complexity of natural systems, such as the swarming and collective behaviors typically observed in animals and microorganisms, for efficient task execution. This study introduces magnetically controlled microrobots that possess polymeric sequestrant "hands" decorating a magnetic core. Under the influence of external magnetic fields, the functionalized magnetic beads dynamically self-assemble from individual microparticles into well-defined rotating planes of diverse dimensions, allowing modulation of their propulsion speed, and exhibiting a collective motion. These mobile microrobotic swarms can actively capture free-swimming bacteria and dispersed microplastics "on-the-fly", thereby cleaning aquatic environments. Unlike conventional methods, these microrobots can be collected from the complex media and can release the captured contaminants in a second vessel in a controllable manner, that is, using ultrasound, offering a sustainable solution for repeated use in decontamination processes. Additionally, the residual water is subjected to UV irradiation to eliminate any remaining bacteria, providing a comprehensive cleaning solution. In summary, this study shows a swarming microrobot design for water decontamination processes.

• Keywords
• collective motion, magnetically driven, micromotors, microplastics, self-assembly, swarming behavior, water purification,
• MeSH
• Bacteria isolation & purification   MeSH
• Escherichia coli isolation & purification   MeSH
• Magnetic Fields MeSH
• Microplastics * chemistry   MeSH
• Polymers chemistry   MeSH
• Robotics * instrumentation   MeSH
• Particle Size MeSH
• Water chemistry   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH