Interactive And Synergistic Behaviours Of Multiple Microrobots

In recent years,externally physic field-driven microrobots have shown great potential in the area of biomedicine,especially in the fields of active targeted drug delivery,medical imaging,and cell manipulation.The overall system can be summarized as material composition,fabrication and processing,actuation control and specific application,etc.The research and innovation of magnetic controlled microrobot mainly revolves around these modules in all aspects,which have made great efforts and achieved remarkable progress.However,most of these studies are based on individual microrobots with limited capabilities,which limits their functional scalability in practical applications.Inspired by nature,multiple animals interact with multiple individuals to perform tasks that many individuals cannot.The interaction and cooperation among multiple microrobots also have the potential to accomplish tasks that a single microrobot could not.Therefore,this topic studies the interactive and cooperative behaviours among multi-microrobots,so as to lay the foundation for the multi-microrobot system to play a practical role.First of all,this topic studies the interactive and cooperative behaviours among multiple microrobots with different properties(which refers to having the same shape structure but different characteristics)or not completely homogeneous under the low frequency rotating magnetic field.The frequency response theory is proposed based on the production of gear-shaped microrobots with different magnetic particle configurations.Different types of micro-gears have the same characteristics as well as obvious differences,that is,under the rotating magnetic field within a certain frequency range,they all rotate along with the rotation of the external rotating magnetic field.When exceeding a certain frequency(critical frequency),the complete rotating motion will be broken,resulting in the decrease of rotational speed.This behaviour is even more pronounced in micro-gears with neatly arranged magnetic particles.By further exploring the influence of various parameters on the critical frequency of the micro-gears,it is possible to customize the micro-gears of different quality with specific critical frequency.In addition,experiments and simulations were used to investigate the effects of rotating micro-gears at different frequencies on the surrounding fluid,and to demonstrate the interactive and cooperative behaviours of multiple micro-gears with different qualities or incomplete homogeneity.Then,the reversible interaction and cooperation between multiple microrobots in a higher frequency range(<15 Hz)is studied by using two different sizes of disk-like microrobots.The behaviour of a single microrobot is studied in the critical frequency range of microrobot.The reversible state transformation between pairs of micromachines is analysed theoretically and the frequency dependence law is given in the interaction mode.The trajectory changes of three microrobot combinations at different frequencies and the reversible transformation between different modes are analysed.Finally,the interactive steady-state mode of different combinations and the dynamic switching between the interaction and cooperative behaviour of microrobots are shown.To sum up,the microsystems and methods based on multi-microrobots proposed in this subject will be helpful to the development and design of dynamic microsystems or microrobotic systems for different applications.It has important implications for multimicrorobots to perform multi-tasks and cooperate to perform complex tasks and has great practical application potential in biomedical applications.