writer：Kai Feng, Wenqi Shen, Ling Chen, Jiang Gong, Thomas Palberg, Jinping Qu, Ran Niu*
keywords：Micromotor swarm, drug delivery
source：期刊
Issue time：2023年

Swimming microrobots that are actuated by multiple stimuli/fields display various intriguing

collective behaviors, ranging from phase separation to clustering and giant number fluctuation; however, it is still chanllenging to achieve multiple responses and functionalities within one colloidal system to emulate high environmental adaptability and improved tasking capability of natural swarms. In this work, we present a weak ion-exchange based swarm that can self-organize and reconfigure by chemical, light and magnetic fields, showing living crystal, amorphous glass, liquid, chain and wheel-like structures. By changing the frequency and strength of the rotating magnetic field, various well-controlled and fast transformations were obtained. Experiments show the high adaptability and functionality of the microrobot swarm in delivering drugs in confined spaces, such as narrow channels with turns or obstacles. The drug-carrying

swarm exhibits excellent chemtherapy for Hela and CT26 cells due to the pH-enhanced drug release and locomotion. This reconfigurable microswarm provides a new platform for biomedical and environmental applications.