MEMS inductor fabrication and emerging applications in power electronics and neurotechnologies

Abstract

MEMS inductors are used in a wide range of applications in micro- and nanotechnology, including RF MEMS, sensors, power electronics, and Bio-MEMS. Fabrication technologies set the boundary conditions for inductor design and their electrical and mechanical performance. This review provides a comprehensive overview of state-of-the-art MEMS technologies for inductor fabrication, presents recent advances in 3D additive fabrication technologies, and discusses the challenges and opportunities of MEMS inductors for two emerging applications, namely, integrated power electronics and neurotechnologies. Among the four top-down MEMS fabrication approaches, 3D surface micromachining and through-substrate-via (TSV) fabrication technology have been intensively studied to fabricate 3D inductors such as solenoid and toroid in-substrate TSV inductors. While 3D inductors are preferred for their high-quality factor, high power density, and low parasitic capacitance, in-substrate TSV inductors offer an additional unique advantage for 3D system integration and efficient thermal dissipation. These features make in-substrate TSV inductors promising to achieve the ultimate goal of monolithically integrated power converters. From another perspective, 3D bottom-up additive techniques such as ice lithography have great potential for fabricating inductors with geometries and specifications that are very challenging to achieve with established MEMS technologies. Finally, we discuss inspiring and emerging research opportunities for MEMS inductors.

Application of DC-DC Converter in Sensor and MEMS Device Integration and Packaging

“…Several key technologies of DC converter chips are studied [2]. There is a body diode turn-on and turn-off process, the application of bidirectional DC-DC converters will introduce new losses [3][4][5], and the optimal design for the control and drive of this type of converter has not been able to obtain a better solution [6]; therefore, studying the optimal driving method of RC-IGBT (reverse conducting IGBT) bidirectional DC-DC converter can provide an effective solution to the problem of RC-IGBT body diode characteristics in the bidirectional DC-DC converter scenario, which is helpful for ensuring the reliability of this type of converter [7].…”

Design, Modeling, and Analysis of a 3-D Spiral Inductor With Magnetic Thin-Films for PwrSoC/PwrSiP DC-DC Converters

“…In-plane magnetic field in a 3D inductor [38] (https://creativecommons.org/licenses/by/4.0/). ✗ As 2D spiral inductors are comprised of only planar conductors, the magnetic field is always out-of-plane.…”

Femtosecond Laser Ablation Assisted NFC Antenna Fabrication for Smart Contact Lenses

“…[ 51–53 ] Although microfabrication yields highly precise dimensions, the thickness of the deposited Au is in the range of 100 to 150 nm leading to a high resistance for the antenna and consequently a considerable degradation in its performance. [ 54 ] Based on theory, increasing the antenna lines’ width can help decrease the total resistance. However, this increases total antenna size and leads to vision impairments as Au is not transparent.…”