Professor Wang Huaping from the Institute of Intelligent Robotics of Beijing Institute of Technology has made important progress in the field of micro nano robots and biomedical engineering. On December 14, his research achievement "Programmable aniso electrodeposited modular hydrogel microrobots" was published online in the scientific sub journalScience Advancein the form of a long research article. This achievement is the first to create an integrated manufacturing method of single film software micro robot with arbitrary configuration that can integrate different functions and deformation modules, thus solving the adaptability problem of micro robot to simultaneously carry out multi sequence complex tasks such as development, drug delivery, repair, etc. in the closed environment of living bodies such as human bodies, and providing a new idea for developing more intelligent, more integrated, and more efficient treatment methods for major diseases such as cancer.

Professor Wang Huaping of the Institute of Mechanical and Electrical Engineering and Professor Metin Sitti of the German Max Planck Institute are the corresponding authors of the paper, Zheng Zhiqiang (postdoctoral fellow of the Max Planck Institute), a doctoral graduate of the Institute of Mechanical and Electrical Engineering, is the first author of the paper, and Beijing University of Technology is the first author of the paper.

Fig. 1 Heterogeneous electrodeposition manufacturing principle and living operation diagram of modular software micro robot

In recent years, soft micro robots have received extensive attention due to their morphological variability, physical adaptability and mutual friendliness, and have shown great potential in personalized cutting-edge medical fields such as cancer targeted therapy. At present, micro robots can complete specific tasks by carrying specific substances and moving and deforming under the stimulation of physical fields such as light, electricity and magnetism. However, most of the micro robot bodies can only carry a specific single function, which is difficult to meet the task requirements of multi sequence complex operations in real life scenes. In contrast, natural creatures have different functional modules such as driving, sensing, decision-making and operation through long-term evolution, which can effectively adapt to complex environments. Inspired by this, the development of a modular micro robot with multiple components and composite functions is of great significance for flexibly carrying out the whole process operation in the organism and greatly improving the intelligence and efficiency of non-invasive medical treatment.

Modular and Integrated Design -- Transforming Micro Robot Composite Manufacturing Mode

On the basis of previous research on the automorphic alginic acid micro robot (Nature Communications, vol. 12 (1), 2021 https://doi.org/10.1038/s41467-020-20697-w ）And further explored how the alginate liquid solidified into the gel composed of different size grid structures under the action of non-uniform electric field. It is found that these grid structures can not only expand and shrink when stimulated by changes in ion concentration and pH value, so that the gel as a whole shows specific deformation characteristics, but also act as a mesh envelope to embed components of various particle sizes. This discovery inspired the team to develop modular micro robots that can integrate different deformation modes and functional components.

The team preset the overall shape of the micro robot and divided it into different module areas. In each area, electrodes matching the local shape of the robot were deployed and alginate solutions mixed with different functional components were injected. By adjusting the electric field direction and gradient of each area, the micro robot body is integrated by synchronous electrodeposition solidification of multiple areas. Such micro robot not only has the overall configuration of degradable alginate gel single film, but also can maintain its unique deformation mode and biological function of each local module, changing the cumbersome manufacturing mode of the current composite software micro robot, and greatly improving the functionality of the single film micro robot.

Fig. 2 Manufacturing process of modular micro robot with multiple deformation modes and composite biological functions

Multicomponent and multimodal composition - the whole process of service targeted medical tasks

Through the modular software micro robot manufacturing method, the team designed the classic strip micro robot body structure, and loaded different materials such as magnetic nanoparticles, contrast agents (such as microbubbles and fluorescent nanoparticles), functional cells, and targeted drugs for its different module areas, so that it can have the performance of magnetic drive, closed space development feedback, targeted operation, etc. By endowing different modules of the micro robot body with specific deformation modes, the micro robot body can sense the changing body fluid ion concentration and pH value in the living environment, produce coaxial and off-axis deformation in local areas, and simulate caterpillar wriggle and fish wagging through magnetic drive, so as to achieve multiple sequence complex tasks such as transportation, delivery, transplantation, recovery, degradation, which is expected to make a great effort in the future personalized targeted medicine.

Fig. 3 Multi sequence operation of "transport – delivery- transplantation- recovery" of functional cells by modular micro robot

By effectively using the modular software micro robot processing strategy, the team will continue to explore the single control and group cooperation methods of multi module micro robots in the future, provide enabling support for cross domain collaboration and adaptive work in complex living environment, and serve the whole process of precise medical tasks such as lesion location, drug administration, repair, etc.

Team introduction attached:

The biological micro nano operation team of Beijing Institute of Technology has carried out a series of research in micro nano robots, micro nano biological manufacturing and other aspects relying on the School of Mechanical and Electrical Engineering and facing the world's leading edge. Relevant achievements have been published in such internationally renowned journals asScience Advance,Nature Communications,Lab on a Chip,Biofinance,IEEE Transand so on. This paper takes Beijing Institute of Technology as the first unit, and the relevant work was completed by the research team of the Institute of Electromechanical Science and Technology and the German Max Planck Institute, showing that the team has made progress in actively exploring international cooperation models and improving international influence in the field of micro nano robot technology.