09/11/2026
In the pursuit to create targeted drug-delivery robots, a research team led by Lehigh University Mechanical Engineering's Ebru Demir observed unusual behaviors in tiny swimmers traversing Newtonian fluid vs. shear-thinning fluid.
In the footage, both swimmers are actuated from a resting position on a flat wall, with an identical rotating magnetic field. They move forward towards their heads in both fluids. In the Newtonian fluid, the swimmer drifts sideways consistent with its rolling direction. In the shear-thinning fluid (like blood or mucus), it drifts the other way even though it's spinning in the same direction. The wall and the fluid's properties, together, steer the robot.
Another step closer to controlling swimmers to deliver life-saving care. Read more: https://engineering.lehigh.edu/news/article/unexpected-motion-drug-delivery-robots