Application of ferrite coated nanopropellers for measurement of rheological properties of human blood

Controlled maneuvering of artificial nanomotors in various biological environments can have impactful biomedical applications, such as drug delivery, microsurgery etc. In spite of the various strategies available for the fabrication of nanomotors, practical issues such as toxic fuel requirement, corrosion of the nanomotor and the liquid viscosity has limited their usage to simple bio fluids such as serum, diluted urine etc. By incorporating conformal ferrite coatings to our system of magnetic nanopropellers, we have been able to maneuver artificial nanomotors in undiluted human blood. The motion of the nanopropellers in human blood showed an interesting stick and slip motion, originating from the colloidal jamming of the blood cells. The amount of jamming was found to be related to the concentration of the blood cells, and therefore establishes the suitability of the propellers in probing mechanical properties of blood and other interesting suspensions.