Flexible MEMS inductors based on Parylene-FeNi Compound Substrate for wireless power transmission system

In this paper, flexible MEMS inductors based on Parylene-FeNi Compound Substrate (PFCS) were designed, fabricated and analyzed. We choose parylene as substrate to achieve flexibility and good bio-compatibility. Then, a Ni₈₀Fe₂₀ magnetic film was deposited on the parylene film to form a compound substrate. Moreover, a Ni₈₀Fe₂₀ core was also deposited in the center of the spiral inductor to improve its performance. As the radius of magnetic core increased from 800μm to 1200μm, the maximum quality factor and the inductance increased by 288% (from 4.10 to 15.91) and 297% (from 265.94nH to 1.06uH), respectively. If we replaced the magnetic core with magnetic array, the maximum quality factor and the inductance could improve by 111.45% (from 6.29 to 13.30) and 102.78% (from 470.97nH to 955.05nH). Finally, the PFCS inductors were tested in our experimental system.