Developing Magnetic Tweezers for Magnetic Material Manipulation

Single-molecule research has stimulated the development of a wide range of technologies that are capable of manipulating very small structures and materials. Among current available methods, the magnetic tweezers show high efficiency and cost effectiveness in generating strong and direction adjustable interactions with magnetic materials. Since our research group has extensive experience in synthesizing magnetic nanostructures, it is of great interest to develop magnetic force-based nanomaterials manipulation techniques. In this thesis, we describe the design and construct of tip based electromagnetic tweezers. We focused on the investigation and quantification of interactions between a soft magnetic tip and a superparamagnetic bead suspended in liquid. We studied the effects of tip taper length and current in the solenoid surrounding the tip on resulted forces. An axisymmetric 2D model using COMSOL Multiphysics has also been developed to analyze the magnetic field and force acting on the superparamagnetic beads based on experimental design.