Untethered Magnetic Robots (UMRs) show strong potential for medical applications like targeted cancer therapy and other minimally invasive procedures. Screw-shaped UMRs can swim through blood and Newtonian fluids, but steering in viscoelastic soft tissue remains challenging due to instability. Although straight path motion is proven to be possible, precise navigation in the body’s complex network requires improved and controlled steering.
Simulations showed an optimal steering angle ψ of 60°, which was tested on a 1 mm-pitch UMR in a gelatin phantom. To validate the phantom, ex vivo tests on ovine brain and liver were conducted, as well as rheological comparisons with gelatin and liver tissue, demonstrating the design’s relevance for brain applications but notable setbacks with liver tissue.