Magnetically actuated miniature bamboo-fiber robots for antibiotic removal from water

Antibiotic contamination in aquatic environments threatens ecosystem health and water security; yet, efficient, recyclable, and environmentally benign removal remains challenging. Here, a magnetically actuated miniature bamboo-fiber robot (MBFR), functionalized with a porous chitin foam, is demonstrated for antibiotic removal from complex water matrices. Bamboo and chitin afford biodegradability and facile fabrication, while Fe₃O₄ nanoparticles enable fuel-free magnetic actuation, directional propulsion, and magnetic retrieval. The chitin foam provides abundant binding sites for broad-spectrum antibiotic capture through cooperative noncovalent interactions. Magnetic actuation accelerates interfacial mass transfer, with maximum adsorption capacities of 435.60 mg/g for norfloxacin (NOR) and 391.69 mg/g for oxytetracycline (OTC). After 20 adsorption-desorption cycles in natural-water matrices, MBFRs retained over 90% NOR removal and remained effective under representative matrix interferences. This work may open up prospects for functional biomass-derived robots in the active and recyclable remediation of antibiotic-contaminated waters.