Experimental characterization of helical propulsion in Newtonian and viscoelastic mediums

This work in vestigates the locomotion of helical robots in a low Reynolds number environment with two different rheological properties. We study the swimming characteristics of the robot during its transition from a Newtonian fluid to a viscoelastic environment. Our experimental results show that the helical robot causes shear thinning in gelatin with intermediate concentration. Therefore, its speed in gelatin is greater than that in silicone oil. The helical robot swims at maximum speed of 0.36 mm/s in silicone oil with viscosity of 5 Pa.s, and 0.22 mm/s, 0.71 mm/s, and 0.94 mm/s in gelatin with concentration of 2%, 3% and 4%, respectively, under the influence of two rotating dipole fields.