A novel microactuator device based on magnetic nanofluid

This paper presents the prototype of an actuator that utilizes a colloidal, super-paramagnetic, nanometric particles fluid as active medium. The experimental measurements show that magnetic properties of the fluid are adequate to the actuator working conditions. An electronic module for the control of the actuator ferrite cored coils was designed and produced; it implements the pulse width modulation (PWM) principle. The module produces train pulses of adjustable frequency and fill factor to drive the electrical currents in the actuator coils. The magnetic field produced by the actuator coils generates magnetic body forces in the magnetic fluid that add to gravitational forces to drive the fluid in a forced flow. The motion is perceived as periodic stationary surface waves, localized above the actuator coils. Mathematical modeling and numerical simulation (by the finite element method (FEM)) are used to study and evaluate these processes. The heat transfer part of the problem was also studied, although thermal stability proves to be less of a concern. The device may provide a usable actuation resolution, as the results suggests.