Deyuan Zhang

Research on magnetic metallization of bacterial cells

A multidisciplinary approach to the fabrication of biologically based magnetic monomers for biolimited forming is described. Rod-like Bacilli ccreus about 0.5 μ in diameter and 3–5 μm in length, were used as templates on which the ferromagnetic material was deposited by an electroless deposition method. Different electroless plating solutions were compared in detail and CoNiP solution was selected. During the deposition process, both dispersant and mechanical stirring were used to solve the problem of aggregation of bacterial cells so as to obtain a uniform plating layer. The CoNiP film on Bacilli cereus was a mixture of crystalline and non-crystalline in the phase structure and showed a good magnetism. The magnetic metallized bacterial cells could be manipulated with a magnetic field. Parallel arrays of these micro magnetic particles were achieved and they could rotate along with the magnetic field.

Behavior of micromagnetic particles in an opposed-poles orientation magnetic field

Abstract Uniform microparticles with a dimension of about 1xa0μm in diameter and several microns in length, were obtained by an electroless deposition technique of CoNiP on bacilli initiated by molecular palladium catalysts. Water-based magnetic fluid containing the small particles was treated with magnetic fields in order to obtain regular arrays of aligned particles. Using an optical microscope with camera system, real time visualization of the magnetic particles was carried out. Both array and chain-like cluster formation of particles under magnetic field were observed. The interaction with the magnetic fields was also analyzed.

Synthetic Effect of Vivid Shark Skin and Polymer Additive on Drag Reduction Reinforcement

Natural shark skin has a well-demonstrated drag reduction function, which is mainly owing to its microscopic structure and mucus on the body surface. In order to improve drag reduction, it is necessary to integrate microscopic drag reduction structure and drag reduction agent. In this study, two hybrid approaches to synthetically combine vivid shark skin and polymer additive, namely, long-chain grafting and controllable polymer diffusion, were proposed and attempted to mimic such hierarchical topography of shark skin without waste of polymer additive. Grafting mechanism and optimization of diffusion port were investigated to improve the efficiency of the polymer additive. Superior drag reduction effects were validated, and the combined effect was also clarified through comparison between drag reduction experiments.