Simulation Pipeline of Milli-scale Magnetic Robots for Blood Clot Removal

Milliscale, magnetically-controlled robots can be used for targeted blood clot removal. This method may provide a more precise, less dangerous, and less invasive removal process than the current methods which utilize blood thinning medication and catheters. These robots have helical threads so that magnetically induced rotation will produce a propulsive force that is controlled by an external magnetic system. The speed at which the robots need to rotate in order to hover in place in human blood is called the hovering frequency, and was used as a measure of the efficiency of the robot designs. We developed a pipeline for simulated testing of the robots using Finite Element Methods and post-processing. The flow of blood around the robots when rotating at various frequencies was modeled with the Navier-Stokes equations and approximated using the penalty method. In post-processing, the simulations were evaluated by visualizing the interaction of flow lines with the design geometries, confirming that the divergence is approximately zero along the geometry's surface, and calculating the generated propulsive forces. Various physical design parameters including thread depth, air pocket size, tip shape, and pitch, were tested with this method to compare the efficiency of hovering frequencies between simulated models. Future work will involve further optimization of the robot's shapes, evaluation of the model, and automation of the simulation process.