Inspired by natural swimmers such as bacteria, artificial microswimmers hold great potential in becoming controllable agents of micro world. These swimmers can be used in targeted drug delivery, minimally invasive surgery and manipulative agents in microsystems such as lab-on-a-chip devices. Magnetic field is the most preferred actuation mechanism as it allows for in vivo applications.
Part of our research group is concentrated on microswimmers with helical tails which are like Escheria coli bacteria. Experiments are conducted on millimeter-scale swimmers that are produced with 3D printing technology. The swimmers are propelled by a rotating magnetic field inside channels filled with various fluids and the experiments are recorded with a high-speed camera. The trajectories, velocities and orientations of the swimmer are extracted using image processing tools. The change in extracted parameters is investigated with respect to fluid flow, tail geometry, channel size, rotation rate of the magnetic field, and direction of propulsion.
Alongside the experimental studies, various time-dependent and stationary Computational Fluid Dynamics (CFD) models are developed to understand the flow field around the swimmer, efficient swimming conditions, ideal tail geometry and effects of design parameters on swimming. Our time-dependent simulation model can replicate the experimental trajectories and velocities accurately. Trajectory predictions with simulations based on the Resistive Force Theory and other numerical and analytical solutions are also studied.
Our future interests include:
- Effects of coupling the magnetic actuation with ultrasonic waves on the swimming velocity and the trajectory
- Modulating magnetic field to make the swimmer follow a certain path or perform various actions,
- Micro-scale swimmer production by microfabrication methods,
- Investigation of swimming in fluid-fluid interfaces.