Precision impedance analyser for nano and mesoscale materials characterization

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A high precision impedance analyzer is needed to measure the impedance of mesoscopic materials in three distinct areas of Materials Physics research at the University of Manitoba.  These research areas are: 1)  Characterizing the complex, frequency-dependent susceptibility of small volumes of colloidal dispersions of magnetic nanoparticles (i.e., ferrofluids).  These measurements will probe the rotational Brownian motion of nanoparticles, and provide a window into the effects of different nanoparticle coatings (e.g. a drug-covered nanoparticle).  Experiments will provide a measure of the thickness of the coating, and how different coatings affect the motion of nanoparticles through a fluid (relevant to the development of medical applications with magnetic nanoparticles). 2)  Characterizing the electric impedance of magnetic materials that exhibit the recently discovered phenomenon of giant magnetoimpedance (GMI).  These materials are interesting from a pure and an applied viewpoint -- the latter involving product identification codes and counterfeit protection. 3) Shear modulus measurements at ultrasonic frequencies in highly attenuating food systems. In these materials, pulsed transmission techniques typically fail but measurements of the impedance variation of ultrasonic shear wave transducers when loaded with the sample provide a sensitive method for determining the shear modulus.  It is also needed to study drainage of food foams by measuring the variation of impedance with position and time.  These studies will enable new techniques for food quality assesment during production (e.g., a better loaf of sliced bread).