An Overview of Micro/Nanorobot Swarm Control: From Fundamental Understanding to Autonomy

Micro/nanorobots have gained increasing attention worldwide owing to their promising potential in biomedicine. Benefiting from their small size and controllability, micro/nanorobots are ideal candidates for applications including targeted therapy, minimally invasive surgery, and drug delivery in physiological environments. However, the micro/nano-scale dimension hinders the ability and future application of miniature robots in the meantime. In recent years, swarm micro/nanorobotics has emerged as a rapidly developing interdisciplinary field. By simultaneously manipulating multiple micro/nanorobots, a micro/nanoswarm possesses larger delivery dose, better adaptivity to external environments, and better imaging contrast. Unlike macroscale robotic systems, implementing sensors or power supplies on micro/nanorobots is hard to achieve, which brings challenges for the control, feedback, and interagent communication of swarm micro/nanorobotics. In this review, we summarize state-of-the-art research about micro/nanoswarm, including actuation, imaging, and automatic control. Effective driving strategies and feedback methods provide the foundation for practical application. With the assistance of advanced control algorithms, micro/nanoswarms are able to exhibit computational intelligence. Compared to manual control, micro/nanoswarm systems with high-level autonomy is able to conduct bio-tasks with better efficiency and precision. Moreover, the future challenges and directions for micro/nanoswarms are discussed. With this review, we aim to provide a comprehensive understanding and valuable guidance for swarm micro/nanorobotics researchers.