Magnetic Nano and Micro Rods as Tools for Characterizing Materials Mechanical Properties: Fundamentals and Applications

The focus of this dissertation is insect blood (Hemolymph). Hemolymph is analyzed by taking a materials science approach. Rheological characterization of hemolymph has been performed for the first time. Owing to a minute amount of available material, a new protocol was established where Magnetic Rotational Spectroscopy (MRS) with ferromagnetic nanorods was employed. The challenge was examining the microliter droplets' viscosity in less than a few minutes. This challenge was successfully resolved. Blood is critical for the insect's survival: after wounding, the insect has to seal the wound quickly, in a few minutes. As the mechanism of fast clotting has never been discussed from the materials science angle, a set of new experimental protocols has been developed. These protocols and the results allowed the AIMS lab to investigate the surface tension and adhesion characteristics of blood and quantitatively study the kinetics of blood spreading and evaporation. Comparative analysis of blood clotting in butterflies and moths revealed a common feature of wound sealing in these insects: the formation of crust followed by wound sealing. Blood plays a vital role in insect locomotion. A rigorous analysis of the mechanism of dissipation of muscular energy in hovering hawkmoth has been studied. Insects probe the environment using antennae. So far, antennae have been considered as rigid rods or solid beams. The AIMS lab was the first to investigate the mechanical properties of antennae to show that blood plays a significant role in flexing the antennae. However, the dynamic properties of antennae and blood-cuticle coupling were difficult to study. In this dissertation, a series of new experimental methods, engineering models and scientific software are described and used to perform and analyze dynamic experiments on live insects.