Cordless Miniature Robots from Centimeter to Nanometer Scale: Recent Progress and Future Challenges in Biomedicine Field

Abstract The use of robots in healthcare holds promise for improving the quality of life. The miniaturization of robots enables them to work in complex liquid environments in narrow areas of human body. Cordless robots have strong mobility and can reach inaccessible areas; so, they are of great significance in precision and personalized medicine fields. Miniature robots can be divided into two categories: one is robots with millimeter to centimeter size, which are slightly larger in size. It can be equipped with control, monitoring, communication, and other functional modules, realizing imaging monitoring, targeted drug delivery, and other functions. The other is robots with nanometer to micrometer size, which are generally driven by external physical fields due to small size. They are mainly used in imaging, diagnosis, surgery, and drug delivery. However, when miniature robots are used in clinical applications, problems such as power, longevity, and security still need to be considered. This article reviews the driving mechanisms and position technology of miniature robots. In addition, possible solutions to the current clinical challenges are proposed, exploring structures and functions required for future development. This article provides a reference for robots and development of precision medicine.