Recent Advancements in Multimodal Chemically Powered Micro/Nanorobots for Environmental Sensing and Remediation

Chemically powered micro/nanorobots (CPMNRs) are self-propelling artificially engineered materials or machines designed with micro-to-nano precision, inspired by the self-migration of biomolecules and microorganisms. CPMNRs convert chemical or external energy into mechanical motion, overcoming forces like Brownian diffusion and viscosity. They are created using top-down or bottom-up approaches for applications in chemo-/biosensing, environmental remediation, molecular imaging, and drug delivery. As self-mixing of contaminated water accelerates the remediation process, CPMNRs are preferred as an ideal choice for environmental applications. Recent advancements in multimodal propulsion technologies, material engineering, and surface modifications have significantly enhanced the capabilities of CPMNRs, enabling them to navigate complex environments and interact with contaminants at the molecular level. This review highlights the latest developments in chemical-driven CPMNRs, focusing on their use in environmental monitoring, pollutant detection, and remediation of heavy metals, microplastics, and organic contaminants in water and soil. It also discusses prospects, sustainability of chemical fuels, environmental biocompatibility, and scalability for large-scale deployment.