Fabrication of Multi-Axis Moving Coil Type Electromagnetic Micro-Actuator Using Parylene Beams for Pure In-Plane Motion

In this paper, we report a moving coil type electromagnetic micro-actuator, which can achieve multi-axis in-plane motion. Magnetic transduction is the most attractive to various applications, including micromanipulator, gyroscopes, and micro-scanners. There are two types of electromagnetic actuator, a moving magnet type and a moving coil type. Moving coil type is suitable for achieving in-plane displacement by controlling the magnetic field. However, the moving magnet type has the disadvantage of cross-coupled out-of-plane displacement which needs an additional mechanical constrain structure to overcome if pure in-plane actuation is required. In this work, the moving coil type actuator was fabricated, which was formed by four driving units, one center moving stage, and soft parylene beams. Each of the driving units was formed by four driving springs, which were made of silicon and metal and connected by a shuttle. The center moving stage was connected with the four shuttles. In-plane Lorentz force was generated to deform the driving springs by applying current and magnetic field. In the experiment, the relationship between the current and displacement was revealed under different strength of magnetic field. The maximum displacement was
$20\ \mu\mathrm{m}$
by applying 262 mA current under a 0.273 T magnetic field.