Magnetic MEMS and its applications

This research is to investigate the performance of mini and micro devices driven magnetically through simulations and experiments. Micro-Electro-Mechanical Systems (MEMS) invoking magnetic coupling were designed and tested. Scaled up models and numerical simulation of the micro spiral channel flow were also presented.; Magnetic devices can generate larger forces for larger distance than their electrostatic counterparts; the energy density between the magnetic plates is usually larger than that between the electric plates. Properly designed, magnetic actuators can be made to hold high torques with no intervening wires. Magnetic actuation may be considered a feasible method to drive the MEMS with advantages.; Pulsed laser deposition method is used for growing magnetic material to the surface of micro device. Magnetic material properties are investigated. A permanent magnet made of NdFeB is used as a target for pulsed laser deposition to produce the thin film on a micro device which may induce magnetic coupling with external magnet sources. The properties of the thin film formed at different substrate temperatures and effects of external magnetic field to the thin magnetic film are presented.; A mini screw pump invoking the magnetic driven system is demonstrated and its working performance is verified experimentally. The experiment on mini screw pump is to demonstrate the advantages of magnetic coupling and to verify the feasibility of magnetic coupling concept in a real device. The mathematical modeling and numerical simulations for magnetic coupling are also carried out.; Further, the design and microfabrication technologies are introduced for a magnetically driven micro gear and micro viscous pump. Through the study of several experiments, improvements for designs are made.; Due to the challenge in testing the actual microdevices, scaled-up experiments for magnetically driven viscous pumps are made. These studies simulate the performance of the micro size counterpart. In addition, the analyses of flow in micro size channels are made. Boundary conditions required for a proper simulation are discussed. Numerical simulations required for a pump performance are given. The factors to affect the pump performance are discussed based on the theoretical model, experiment and numerical simulation results.