A fully integrated micromagnetic actuator with a multilevel meander magnetic core

To generate and to confine a magnetic flux in the magnetic core and at the same time minimize coil series resistance, low-resistance meander conductors located in a single plane were interwoven with multilevel meander magnetic cores. This ´wrapped´ solenoid (with the core wrapped around the conductor) was fabricated in a fully integrated fashion. A micromagnetic actuator was realized by incorporating a surface micromachined nickel-iron cantilever beam as part of the magnetic circuit of the core. The nickel-iron cantilever beam was 2.5 mu m thick, 25 mu m wide and 780 mu m long, and the magnetic circuit contained 17 turns of meander type solenoid coils. Tip deflection of 4 mu m in the vertical direction was achieved when a DC voltage less than 1 V (and resulting drive current of 600 mA) was applied to the coils. This fully integrated multilevel topology offers a variety of micromagnetic applications, which can be fabricated on the same substrate with an integrated circuit and actuated with low voltages.<>