A Technological Approach for Miniaturization of Three-Dimensional Inductive Levitation Microsuspensions

In this article, we report on a novel technological approach for miniaturization inductive levitating micro-suspension based on the nested 3D micro-coil structures. In the developed approach, each 3D micro-coil is fabricated separately, beginning with the innermost and thus smallest coil diameter of the nested microstructure. This helps to overcome fabrication restrictions due to the wire-bonding process and primarily caused by the size of the bond-head, and provides the opportunity to fabricate nested 3D micro-coil structures of a smaller size. We fabricated a nested two-micro-coil structure, the inner coil having a diameter of \SI{1000}{\micro\m} and 14 windings, the outer coil with a diameter of 1900m and 8 windings, and demonstrate its application as an inductive levitating micro-suspension. In particular, a fabricated 3D inductive levitating micro-suspension was able to levitate a 1100m diameter disc-shaped proof mass to a height up to 45m.