Browsing by Author "Ramos, Jocelyn"
Now showing 1 - 2 of 2
- Results Per Page
- Sort Options
Item Improving Capabilities and Performance of Magnetic Mili-Scale Swimmers(2022-04-14) Ramos, JocelynMilli-swimmers are small, magnetically controlled robots with helical geometries that create a propulsive thrust with rotational movement. In previous work, milli-swimmers have proved capable of accomplishing tasks in vitro like the abrasion of blood clots. This project is an exploration of the further capabilities and performance of these milli-scale swimmers. One conceptual design explores the ability for a device to deliver and place a stent, enabled by a flexible 3D printed profile. Variations of swimmer designs were fabricated and tested experimentally to compare with simulated models. Simulations using computational fluid dynamics software and the Navier Stokes equations were performed in order to predict the angular velocity needed to keep each design suspended at a neutral position in a blood-mimicking fluid. This velocity is used to judge performance of the swimmers in order to isolate variables that most influence their navigational ability. These parameters may be used in an automated design optimization so that specialized devices can be made for various purposes and patient needs. Further work in this field could potentially enable new types of surgery with highly specialized biomedical devices being used at smaller scales than have been accomplished before.Item Simulation Pipeline of Milli-scale Magnetic Robots for Blood Clot Removal(2020-09-29) Ramos, Jocelyn; Lai, Joyce; Lu, YitongMilliscale, 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.