MEMS inductor fabrication and emerging applications in power electronics and neurotechnologies

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.

Imaging atomic-scale chemistry from fused multi-modal electron microscopy

Efforts to map atomic-scale chemistry at low doses with minimal noise using electron microscopes are fundamentally limited by inelastic interactions.Here,fused multi-modal electron microscopy offers high signal-to-noise ratio(SNR)recovery of material chemistry at nano-and atomic-resolution by coupling correlated information encoded within both elastic scattering(high-angle annular dark-field(HAADF))and inelastic spectroscopic signals(electron energy loss(EELS)or energy-dispersive x-ray(EDX)).By linking these simultaneously acquired signals,or modalities,the chemical distribution within nanomaterials can be imaged at significantly lower doses with existing detector hardware.In many cases,the dose requirements can be reduced by over one order of magnitude.This high SNR recovery of chemistry is tested against simulated and experimental atomic resolution data of heterogeneous nanomaterials.