Development of Millirobot for Medical Application


Hong Kong


Millirobots that can adapt to unstructured environments, operate in confined spaces and interact with a diverse range of objects would be desirable for exploration and biomedical applications. The continued development of millirobots, however, requires simple and scalable fabrication techniques. Here we propose a minimalist approach to construct millirobots by coating inanimate objects with a composited agglutinate magnetic spray. Our approach enables a variety of 1-D, 2-D, or 3-D objects to be covered with a thin magnetically drivable film (~100-250 micrometers in thickness). The film is thin enough to preserve the original size, morphology and structure of the objects while providing actuation of up to hundredfold of its own weight. Under the actuation of a magnetic field, our millirobots are able to demonstrate a range of locomotive abilities: crawling, walking, and rolling. Moreover, we can reprogram and disintegrate the magnetic film on our millirobots on demand. We leverage these abilities to demonstrate biomedical applications, including catheter navigation and drug delivery.


•    Benefiting from the spray form and the self-adhesive ability of the developed material, our method is capable of converting multifarious objects ranging from 1D to 3D, and from milli- to centimeter, making it be a common solution for the millirobot construction. •    After turned into a robot, the dimension and structure change of the object is neglectable, because the fabrication only needs a thin layer (~100-200 mm) of agglutinate magnetic spray, which are of import for the object operation at limited space. •    It can fully use the structure of object for locomotion, leading to a high actuation efficiency. •    Profit from peculiarities of adaptiveness, reprogramming and disintegration, the topology order of the robot can be rewritten freely after fabrication and disintegrate themselves after completing the task, leading to great potentials for practical applications in biomedical engineering.


•    Active catheter: We can covert the passive catheter to an active one by a simple coating process. The diameter increase of the catheter is almost neglectable. Moreover, the catheter can be programmed to bend at different angles. •    Drug delivery: We can convert the conventional pills or capsules to an active delivery system.  We can take the pills and capsules to the target region and release it controllably. •    Other manipulation and transportation in unpredictable and limited space.


A millirobot construction technique that can find wide applications in biomedcial engineering.