Magnetically controlled microcarriers for droplet manipulation and heavy metal detection

Droplet manipulation technology has shown excellent prospects in micro-sample transportation, cell culture, and environmental monitoring applications due to its advantages of low reagent consumption, high efficiency, and strong controllability. However, droplet manipulation technology still faces challenges in control performance, limited environmental adaptability, and inadequate contamination protection. Inspired by the structure of Patelloida striata, which protects the body from external damage and enables synchronized movement, the flying saucer-shaped magnetically controlled microcarrier (FSM) was developed using three-dimensional printing and molding methods. Applying magnetic fields ranging from 20 to 300 mT, the FSM captures, transports, releases, and rotates captured droplets with high flexibility and precision. Moreover, the FSM demonstrates excellent compatibility and adaptability, operating effectively across diverse media, such as oil and water, and handling various target liquids, solids, and gases. The FSM has also been successfully used to rapidly and accurately detect copper ions and urease. This study presents the FSM as a novel approach for developing high-performance, environmentally adaptable, and cross-medium droplet manipulation technology.