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Fabrication and Feasibility of Through Silicon Via for 3D MEMS Resonator Integration

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Fabrication and Feasibility of Through Silicon Via for 3D ME...

IEEE Sensors

作者： Alper Kaan Soydan Muhammed Berat Yuksel Dilek Isik Akcakaya Haluk Kulah Micro and Nano Technology Graduate Program Middle East Technical University Ankara Turkey Department of Electrical and Electronics Engineering Middle East Technical University Ankara Turkey

In this study, development of a wafer level, void free TSV fabrication process flow and feasibility study of TSV integration to MEMS piezoelectric resonator devices have been presented. TSV structures with 100 μm diameter and 350 μm depth were copper filled with via sealing and bottom-up electroplating process which is a two-step technique. Four-point Kelvin measurements showed 0.8 mΩ TSV resistance on fabricated TSVs. Furthermore, TSV frames were epoxy bonded to MEMS acoustic transducers, which showed 90% to the resonator signal from the TSV.

关键词： Through silicon via Electroplating MEMS resonator Kelvin measurement Cochlear implant

Planning on discrete event systems using parallelism maximization

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arXiv 2019年

作者： Alves, Lucas V.R. Pena, Patricia N. Takahashi, Ricardo H.C. Technical College and Graduate Program in Electrical Engineering Universidade Federal de Minas Gerais Department of Electronics Engineering Universidade Federal de Minas Gerais Department of Mathematics Universidade Federal de Minas Gerais

This work aims to present solutions for a production planning problem in Discrete Event Systems. The application of Supervisory Control Theory limits the search universe to safe production sequences, so it makes sense to use the supervisor structure, which defines the closed loop behavior, to determine the best sequences. Two efficient solutions to the problem are proposed, and both seek to maximize the parallelism as a way to minimize the makespan. Note to Practitioners-Planning plays an important role in manufacturing systems, but is also a time consuming task. This paper presents simple and fast algorithms to plan the production of manufacturing systems modeled as Discrete Event Systems (DES) maximizing parallelism instead o minimizing the production time (makespan). The idea behind these algorithms is that, reducing the number of idle equipment we increase productivity, given we are maximizing the used resources. Copyright © 2019, The Authors. All rights reserved.

关键词： Discrete event simulation

Tube-based MPC with Nonlinear Control for Load Transportation using a UAV

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IFAC-PapersOnLine 2018年第25期51卷 459-465页

作者： Santos, Marcelo A. Ferramosca, Antonio Raffo, Guilherme V. Graduate Program in Electrical Engineering Federal University of Minas Gerais Belo HorizonteMG Brazil CONICET UTN Facultad Regional Reconquista SantaFe 3560 Argentina Department of Electronics Engineering Federal University of Minas Gerais Belo HorizonteMG Brazil

This paper presents a two-stage cascade control framework to solve hierarchically the trajectory tracking problem of a Tilt-rotor Unmanned Aerial Vehicle (UAV) carrying a suspended load. Initially, a nonlinear dynamic model is presented, which is after decoupled into two subsystems. The outer control system is designed by means of a robust tube-based Model Predictive Control (MPC) strategy, which is used to control the UAV's planar motion and stabilize the suspended load. For the inner control system, the input-output feedback linearization (IOFL) technique combined with the dynamic extension approach and a discrete mixed H2/H∞ controller is considered to control the UAV's altitude and attitude. Simulations results are carried out to corroborate the proposed control strategy. © 2018

关键词： Aircraft control Aircraft detection Altitude control Antennas Cascade control systems Feedback linearization Model predictive control Predictive control systems Unmanned aerial vehicles (UAV) Cascade control Control strategies Dynamic extension Input output feedback linearization Non linear control Planar motion Suspended loads Trajectory tracking problems

Implementation of generalized Harvey-Shack theory in light scattering from rough surfaces

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Physical Review A 2020年第6期102卷 063521-063521页

作者： M. Günöven H. Nasser M. Ünal Ö. Aytekin R. Turan A. Bek Micro and Nanotechnology Program of Graduate School of Natural and Applied Sciences Middle East Technical University 06800 Ankara Turkey Center for Solar Energy Research and Applications Middle East Technical University 06800 Ankara Turkey KalyonPV Research and Development Center Kalyon Güneş Teknolojileri Üretim A.Ş. 06909 Ankara Turkey Department of Physics Middle East Technical University 06800 Ankara Turkey Department of Electrical and Electronics Engineering Kırklareli University 39100 Kırklareli Turkey

We present a discrete implementation of generalized Harvey-Shack scalar scattering theory to calculate angular intensity distributions from height profiles of select randomly textured surfaces proposed for use in solar cells and covering a wide range of surface characteristics. We compare these calculations to high-resolution angular intensity distribution measurements. These comparisons suggest that the pupil function does benefit from an additional correction factor for rough surfaces containing lateral feature sizes on the order of the wavelength, which can be attributed to effective medium effects. Moreover, secondary interactions within the surface topography are shown to be a mechanism that partly redistributes scattered power, affecting angular intensity distribution results. These mechanisms emerge as the two main limitations of the Harvey-Shack scalar scattering theory in the far field, which nonetheless produces remarkable quantitative predictions.

关键词： Interference & diffraction of light Light propagation, transmission & absorption Topological effects in photonic systems Light scattering

Shot noise in a strange metal

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arXiv 2022年

作者： Chen, Liyang Lowder, Dale T. Bakali, Emine Andrews, Aaron Maxwell Schrenk, Werner Waas, Monika Svagera, Robert Eguchi, Gaku Prochaska, Lukas Wang, Yiming Setty, Chandan Sur, Shouvik Si, Qimiao Paschen, Silke Natelson, Douglas Applied Physics Graduate Program Rice University 6100 Main St. HoustonTX77005 United States Department of Physics and Astronomy Rice Center for Quantum Materials Rice University 6100 Main St. HoustonTX77005 United States Institute of Solid State Physics TU Wien Wiedner Hauptstraße 8-10 Vienna1040 Austria Institute of Solid State Electronics TU Wien Gußhausstraße 25-25a Gebäude CH Vienna1040 Austria Center for Micro and Nanostructures TU Wien Gußhausstraße 25-25a Gebäude CH Vienna1040 Austria Department of Electrical and Computer Engineering Rice University 6100 Main St. HoustonTX77005 United States Department of Materials Science and NanoEngineering Rice University 6100 Main St. HoustonTX77005 United States

Strange-metal behavior has been observed in materials ranging from high-temperature superconductors to heavy fermion metals. In conventional metals, current is carried by quasiparticles;although it has been suggested that quasiparticles are absent in strange metals, direct experimental evidence is lacking. We measured shot noise to probe the granularity of the current-carrying excitations in nanowires of the heavy fermion strange metal YbRh2Si2. When compared with conventional metals, shot noise in these nanowires is strongly suppressed. This suppression cannot be attributed to either electron-phonon or electron-electron interactions in a Fermi liquid, which suggests that the current is not carried by well-defined quasiparticles in the strange-metal regime that we probed. Our work sets the stage for similar studies of other strange metals. Copyright © 2022, The Authors. All rights reserved.

关键词： Nanowires

Human brain mapping with multi-thousand channel PtNRGrids resolves novel spatiotemporal dynamics

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arXiv 2021年

作者： Tchoe, Youngbin Bourhis, Andrew M. Cleary, Daniel R. Stedelin, Brittany Lee, Jihwan Tonsfeldt, Karen J. Brown, Erik C. Siler, Dominic Paulk, Angelique C. Yang, Jimmy C. Oh, Hongseok Ro, Yun Goo Choi, Woojin Lee, Keundong Russman, Samantha Ganji, Mehran Galton, Ian Ben-Haim, Sharona Raslan, Ahmed M. Dayeh, Shadi A. Integrated Electronics and Biointerfaces Laboratory Department of Electrical and Computer Engineering University of California San Diego San DiegoCA92093 United States Department of Neurological Surgery University of California San Diego San DiegoCA92093 United States Department of Neurological Surgery Oregon Health & Science University Mail Code CH8N 3303 SW Bond Avenue PortlandOR97239-3098 United States Department of Obstetrics Gynecology and Reproductive Sciences Center for Reproductive Science and Medicine University of California San Diego San DiegoCA92093 United States Department of Neurology Massachusetts General Hospital BostonMA02114 United States Department of Neurosurgery Massachusetts General Hospital BostonMA02114 United States Graduate Program of Materials Science and Engineering University of California San Diego San DiegoCA92093 United States

Electrophysiological devices are critical for mapping eloquent and diseased brain regions and for therapeutic neuromodulation in clinical settings and are extensively utilized for research in brain-machine interfaces. However, the existing devices are often limited in either spatial resolution or cortical coverage, even including those with thousands of channels used in animal experiments. Here, we developed scalable manufacturing processes and dense connectorization to achieve reconfigurable thin-film, multi-thousand channel neurophysiological recording grids using platinum-nanorods (PtNRGrids). With PtNRGrids, we have achieved a multi-thousand channel array of small (30 μm) contacts with low impedance, providing unparalleled spatial and temporal resolution over a large cortical area. We demonstrate that PtNRGrids can resolve sub-millimeter functional organization of the barrel cortex in anesthetized rats that captured the histochemically-demonstrated structure. In the clinical setting, PtNRGrids resolved fine, complex temporal dynamics from the cortical surface in an awake human patient performing grasping tasks. Additionally, the PtNRGrids identified the spatial spread and dynamics of epileptic discharges in a patient undergoing epilepsy surgery at 1 mm spatial resolution, including activity induced by direct electrical stimulation. Collectively, these findings demonstrate the power of the PtNRGrids to transform clinical mapping and research with brain-machine interfaces and highlights a path toward novel therapeutics. Copyright © 2021, The Authors. All rights reserved.

关键词： Mapping

Guaranteed methods based on constrained zonotopes for set-valued state estimation of nonlinear discrete-time systems

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arXiv 2019年

作者： Rego, Brenner S. Raffo, Guilherme V. Scott, Joseph K. Raimondo, Davide M. Graduate Program in Electrical Engineering Federal University of Minas Gerais Belo Horizonte MG 31270-901 Brazil Department of Electronics Engineering Federal University of Minas Gerais Belo Horizonte MG 31270-901 Brazil Department of Chemical and Biomolecular Engineering Clemson University ClemsonSC United States Department of Electrical Computer and Biomedical Engineering University of Pavia Italy

This paper presents new methods for set-valued state estimation of nonlinear discrete-time systems with unknown-but-bounded uncertainties. A single time step involves propagating an enclosure of the system states through the nonlinear dynamics (prediction), and then enclosing the intersection of this set with a bounded-error measurement (update). When these enclosures are represented by simple sets such as intervals, ellipsoids, parallelotopes, and zonotopes, certain set operations can be very conservative. Yet, using general convex polytopes is much more computationally demanding. To address this, this paper presents two new methods, a mean value extension and a first-order Taylor extension, for efficiently propagating constrained zonotopes through nonlinear mappings. These extend existing methods for zonotopes in a consistent way. Examples show that these extensions yield tighter prediction enclosures than zonotopic estimation methods, while largely retaining the computational benefits of zonotopes. Moreover, they enable tighter update enclosures because constrained zonotopes can represent intersections much more accurately than zonotopes. Copyright © 2019, The Authors. All rights reserved.

关键词： Enclosures

Power Routing to Enhance the Lifetime of Multiphase Drives

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Power Routing to Enhance the Lifetime of Multiphase Drives

IEEE Energy Conversion Congress and Exposition

作者： Victor N. Ferreira Rodrigo R. Bastos Tamires S. de Souza Marco Liserre Braz J. Cardoso Filho Chair of Power Electronics Christian-Albrechts-Universität Kiel Germany Graduate Program in Electrical Engineering Universidade Federal de Minas Gerais Belo Horizonte MG Brazil Department of Electro Electronics Instituto Federal de Educação Gerais Brazil Electrical Engineering Department Universidade Federal de Minas Gerais Belo Horizonte MG Brazil

The unbalanced power operation of multiphase machines has been proposed for fault tolerance purpose. However, the higher number of phases, increases the complexity of its power converter. Therefore, design issues can generate thermal deviation among the devices, causing extra heating, and ultimately reducing the lifetime of the most stressed devices. This work proposes the power routing in multiphase drives to reduce the thermal stress of specific devices, increasing the system lifetime. In this strategy, the soft unbalanced operation of multiphase machines is explored, reducing power of the hotter phases and redistributed among the others. Finite element analysis (FEM) and other simulation results show that the strategy can be applied maintaining the same power level and magnetomotive force (MMF) of the balanced operation. A case study is conducted demonstrating the lifetime enhancement of inverters, when power routing is applied in industrial multiphase drives.

关键词： Routing Induction machines Degradation Current control Heating systems Force Reliability

Nano functional neural interfaces

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Nano Research 2018年第10期11卷 5065-5106页

作者： Yongchen Wang Hanlin Zhu Huiran Yang Aaron D. Argall Lan Luan Chong Xie Liang Guo Department of Biomedical Engineering The Ohio State University Columbus 43210 USA Department of Biomedical Engineering The University of Texas at Austin Austin 78712 USA Department of Electrical and Computer Engineering The Ohio State University Columbus 43210 USA Key Laboratory of Flexible Electronics and Institute of Advanced Materials Jiangsu National Synergetic Innovation Center for Advanced Materials Nanjing Tech University Nanjing 211816 China Biomedical Sciences Graduate Program The Ohio State University Columbus 43210 USA Department of Neuroscience The Ohio State University Columbus 43210 USA

Engineered functional neural interfaces （fNIs） serve as essential abiotic-biotic transducers between an engineered system and the nervous system. They convert external physical stimuli to cellular signals in stimulation mode or read out biological processes in recording mode. Information can be exchanged using electricity, light, magnetic fields, mechanical forces, heat, or chemical signals. fNIs have found applications for studying processes in neural circuits from cell cultures to organs to whole organisms, fNI-facilitated signal transduction schemes, coupled with easily manipulable and observable external physical signals, have attracted considerable attention in recent years. This enticing field is rapidly evolving toward miniaturization and biomimicry to achieve long-term interface stability with great signal transduction efficiency. Not only has a new generation of neuroelectrodes been invented, but the use of advanced fNIs that explore other physical modalities of neuromodulation and recording has begun to increase. This review covers these exciting developments and applications of fNIs that rely on nanoelectrodes, nanotransducers, or bionanotransducers to establish an interface with the nervous system. These nano fNIs are promising in offering a high spatial resolution, high target specificity, and high communication bandwidth by allowing for a high density and count of signal channels with minimum material volume and area to dramatically improve the chronic integration of the fNI to the target neural tissue. Such demanding advances in nano fNIs will greatly facilitate new opportunities not only for studying basic neuroscience but also for diagnosing and treating various neurological diseases.

关键词： neural interface neurotechnology nanoelectrode nanomaterial neural recording neural stimulation