Article
Nanoscience & Nanotechnology
Nabil Shalabi, Kyle Searles, Kenichi Takahata
Summary: Switch mode capacitive pressure sensors are innovative microfabricated devices that convert pressure into electric capacitance signals through mechanical switches. These sensors offer zero power consumption, high sensitivity, and high signal-to-noise ratio. By combining switch leads and touch mode analog capacitive sensing, the sensor achieves significantly improved performance compared to commercial sensors. Moreover, the prototype sensor demonstrates the potential for wireless pressure tracking.
MICROSYSTEMS & NANOENGINEERING
(2022)
Article
Engineering, Electrical & Electronic
Ilia V. Uvarov
Summary: This paper describes a failure mechanism of electrostatically actuated MEMS switch related to the migration of adhesive material in a dielectric substrate. The specific process leading to device failure involves the formation of nanoscale structures consisting of Cr and C, which grow into micrometer-sized formations during operation, causing stiction or short circuiting. In addition to the electrode gap, Cr and C also agglomerate into spots and droplets around the gate and its connecting line.
MICROELECTRONICS RELIABILITY
(2021)
Article
Chemistry, Physical
A. M. Engwall, L. B. Bayu Aji, A. A. Baker, S. J. Shin, J. H. Bae, S. K. McCall, J. D. Moody, S. O. Kucheyev
Summary: The study investigated the effects of substrate tilt on properties of gold-tantalum alloy films deposited by magnetron sputtering. It was found that the deposition rate and film density decrease with increasing substrate tilt angle, leading to changes in film properties such as porosity and electrical resistivity. The critical tilt angle for increased resistivity was determined to be between 40 and 60 degrees.
APPLIED SURFACE SCIENCE
(2021)
Article
Physics, Applied
Shangru Zhou, Haojie Liu, Jie Ren, Jiahao Tan, Yan Ye, Gaofeng Zhang, Kun Li, Huai Zheng, Sheng Liu
Summary: This paper proposed a method for a liquid-based thermal switch, where a thermal liquid column can be formed through electric field distribution control in a localized heating device. The electric field controls the formation and dissipation of the liquid column, achieving the on-off function of the thermal switch. By controlling different conductive substrates, localized heat transfer can be achieved and the heat transfer position can be precisely regulated. Furthermore, the fluidity of the liquid enables movable heating in the prepared thermal switch.
APPLIED PHYSICS LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Bin Song, Fanliang Li, Fulong Zhu, Sheng Liu
Summary: This study optimized the fabrication process of piezoresistive pressure sensors to enhance their stability and performance. It found that the designed structure and thermal treatment conditions significantly affect the sensor's performance. Atomic scale characterization showed well-proportioned interfaces between different material layers after low-temperature annealing. Additionally, reducing water content in the sensors through high-temperature annealing is crucial for improving their stability.
SENSORS AND ACTUATORS A-PHYSICAL
(2023)
Article
Nanoscience & Nanotechnology
Eunhwan Jo, Hojoon Lee, Jae-Ik Lee, Jongbaeg Kim
Summary: Researchers have developed a 3D nanocomposite based on ceramic-reinforced carbon nanotube arrays for shock-absorbing and energy dissipation in MEMS devices. By integrating the nanocomposite with the microstructure through a batch-fabrication process, the in-plane shock reliability of a designed movable structure has been significantly improved over a wide acceleration range.
MICROSYSTEMS & NANOENGINEERING
(2023)
Article
Engineering, Electrical & Electronic
Yingli Shi, Chao Zhou, Zibo Cao, Yurong He, Jingwen Guo, Chunxin Li, Qianhong Wu, Kui Liang, Yanzhao Li, Yuan Lin
Summary: This paper presents a design and manufacturing method of a flexible radio-frequency microelectromechanical system switch, which can be used in satellite communication. Through simulation analysis, it is found that the switch can maintain RF performance at certain bending radius. It is demonstrated that the switch is insensitive to bending deformation and has stable RF performance.
NPJ FLEXIBLE ELECTRONICS
(2022)
Article
Materials Science, Coatings & Films
Yvonne Moritz, Christina Kainz, Paul Peritsch, Christian Mitterer, Nina Schalk
Summary: TiSiN coatings are highly attractive in the cutting industry due to their excellent mechanical properties and exceptional oxidation resistance. This study investigates the influence of the shielding effect of amorphous SiNx on the nanocrystalline TiN phase during oxidation. The results reveal that amorphous SiNx efficiently shields TiN against oxidation and has higher resistance to oxidation compared to crystalline TiN.
SURFACE & COATINGS TECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
Nicolas Godard, Patrick Grysan, Emmanuel Defay, Sebastjan Glinsek
Summary: Chemical solution deposition (CSD) is a well-known process for making metal oxide functional layers like PZT thin films, which exhibit improved electromechanical response in the presence of {100} orientation. A comparative study of solvents used for CSD shows that PbTiO3 seed layers derived from 1-methoxy-2-propanol are more efficient in promoting {100} orientation and enhancing electrical and piezoelectric properties compared to those derived from 2-methoxyethanol.
JOURNAL OF MATERIALS CHEMISTRY C
(2021)
Article
Engineering, Electrical & Electronic
Liqun Du, Yang Yu, Bowen Yuan, Bingjiang Guo, Chao Wang, Chengquan Du, Junshan Liu
Summary: A nickel omnidirectional MEMS inertial switch was designed to recognize load direction and have uniform threshold distribution, using UV-LIGA multilayer photolithography and compensation methods for dimensional and process errors during fabrication. The switch meets functional requirements and has dynamic thresholds and response times within specifications for recognizing acceleration direction and overload protection.
MICROELECTRONIC ENGINEERING
(2022)
Article
Chemistry, Analytical
Yukang Feng, Han-yu Tsao, N. Scott Barker
Summary: This work presents a design process for mm-wave/THz MEMS switches. The challenges and solutions in switch electrical design, modeling, fabrication, and testing are explored. The switches are designed on silicon and fused quartz substrates, and tested in the 140-750 GHz frequency range. The measurement results show that the switches perform as expected.
Article
Chemistry, Physical
Kong Liu, Bo Chen, Zhengshan J. Yu, Yulin Wu, Zhitao Huang, Xiaohao Jia, Chao Li, Derrek Spronk, Zhijie Wang, Zhanguo Wang, Shengchun Qu, Zachary C. Holman, Jinsong Huang
Summary: Reducing damage caused by sputtering of transparent conductive oxide (TCO) electrodes is crucial for efficient perovskite/silicon tandem solar cells. This study investigates the damage to bathocuproine (BCP) caused by sputtering, highlighting the potential of using tin oxide (SnO2) as a replacement for BCP to improve device performance. The research demonstrates that SnO2 has higher bond energy to resist sputter induced damage and can suppress peeling-off issue during sputtering, providing a wider range of target-substrate distances than BCP.
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
Article
Engineering, Electrical & Electronic
Naibo Zhang, Ruiliang Song, Jun Liu, Jun Yang
Summary: This study presents a packaged THz shunt capacitor MEMS switch with low insertion loss and high isolation characteristics achieved by optimizing equivalent circuit parameters and switch sizes. The switch achieves low insertion loss of less than 2dB from 220 to 280GHz, and isolation of around 16dB from 240 to 320GHz.
IEEE SENSORS JOURNAL
(2021)
Article
Automation & Control Systems
Qiu Xu, Raed Alahmdi, Lvjun Wang, Rodrigo T. Rocha, Mohammad I. Younis
Summary: In this article, a multithreshold microelectromechanical tunable inertial switch is introduced, aiming to provide quantitative information on acceleration while being energy-saving. The device is composed of serpentine springs, a suspended proof mass, and stationary electrodes, allowing for measurement of acceleration in different ranges. Experimental and simulation results validate the reliability and effectiveness of the device concept.
IEEE-ASME TRANSACTIONS ON MECHATRONICS
(2023)
Article
Engineering, Electrical & Electronic
Xiaoyan Tang, Simon Hammersley, Vladimir Markevich, Ian Hawkins, Iain Crowe, Trevor Martin, Tony Peaker, Matthew Halsall
Summary: Comparing GaN Schottky diodes prepared by resistive thermal evaporation and plasma sputter deposition, it was found that diodes prepared by sputter deposition have significantly higher reverse leakage current and contain two defects which may affect device performance.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2021)
Article
Engineering, Electrical & Electronic
Longchang Ni, Burcu Karagoz, Andrew J. Gellman, Maarten P. De Boer
JOURNAL OF MICROMECHANICS AND MICROENGINEERING
(2020)
Article
Materials Science, Multidisciplinary
Longchang Ni, Ryan M. Pocratsky, Maarten P. de Boer
Article
Engineering, Manufacturing
Changho Oh, Maarten de Boer
IEEE TRANSACTIONS ON COMPONENTS PACKAGING AND MANUFACTURING TECHNOLOGY
(2020)
Article
Materials Science, Multidisciplinary
R. Shrestha, J. Cai, M. Naraghi, M. P. de Boer
EXPERIMENTAL MECHANICS
(2020)
Article
Nanoscience & Nanotechnology
Prince S. Singh, Zhiyuan Liang, George M. Pharr, Maarten P. de Boer
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2020)
Article
Geosciences, Multidisciplinary
M. Choukroun, J. L. Molaro, R. Hodyss, E. Marteau, P. Backes, E. M. Carey, W. Dhaouadi, S. Moreland, E. M. Schulson
GEOPHYSICAL RESEARCH LETTERS
(2020)
Article
Nanoscience & Nanotechnology
Longchang Ni, Ryan M. Pocratsky, Maarten P. de Boer
Summary: This work demonstrates the processing, modeling, and characterization of nanocrystalline tantalum (Ta) as a new structural material for microelectromechanical system (MEMS) thermal actuators (TAs). Compared to polysilicon, Ta TAs require less power input, have smaller temperature changes, and operate at a lower voltage, making them compatible with complementary metal oxide semiconductors (CMOS).
MICROSYSTEMS & NANOENGINEERING
(2021)
Article
Materials Science, Multidisciplinary
Nicholas F. Jones, Jack L. Beuth, Maarten P. de Boer
Summary: This study investigates directly bonded junctions in the IN625 to Stainless Steel 304 system, finding that cracking and intermetallic formation are not detected at high IN625 content, but observed at lower IN625 content due to carbide formation. Heat treatments up to 1300 degrees C are conducted to emulate service conditions, with no gross defects developing at junctions in pads with higher IN625 content even at highest temperatures.
JOURNAL OF MATERIALS RESEARCH
(2021)
Article
Engineering, Electrical & Electronic
Longchang Ni, Maarten P. de Boer
Summary: Metal microelectromechanical systems (MEMS) offer high reflectivity and conductivity, commonly processed using organic or inorganic sacrificial layers. However, issues such as hydrogen incorporation leading to compressive stress have been observed during release processes. Alternative sacrificial materials like AlN and Cu have been explored, with Cu showing isotropic release etching at room temperature and AlN above 60 degrees C. Release etching with these materials has shown changes in uniaxial stress levels after structure release.
JOURNAL OF MICROELECTROMECHANICAL SYSTEMS
(2021)
Article
Engineering, Electrical & Electronic
Longchang Ni, Maarten P. de Boer
Summary: By implementing tantalum thermal actuators, a new microelectromechanical test platform is created for testing the mechanical properties of various metals. The platform is suitable for measuring creep of thin films, with excellent specimen alignment and simple robust handling procedures.
JOURNAL OF MICROELECTROMECHANICAL SYSTEMS
(2022)
Article
Nanoscience & Nanotechnology
James T. Best, Mohammad Ayaz Masud, Maarten P. Boer, Gianluca Piazza
Summary: The design, modeling, and experimental validation of a highly scalable phase change electromechanical relay are presented. The relay utilizes phase change material to actuate and change its state. Finite element analysis models were used to predict temperature distributions and quench times, and the experimental results confirmed the accuracy of the models.
ADVANCED ELECTRONIC MATERIALS
(2022)
Article
Metallurgy & Metallurgical Engineering
Jose A. Loli, Amish R. Chovatiya, Yining He, Zachary W. Ulissi, Maarten P. de Boer, Bryan A. Webler
Summary: This work predicts the oxidation-induced mass change of materials with different alloy compositions at 1000 degrees C using an automated machine learning method. The developed machine learning pipeline, trained on the log(10) of mass change per unit area, achieves good prediction results for most alloys. The study also highlights the usefulness of machine learning methods in predicting composition-dependent oxidation behavior, despite its complexities.
OXIDATION OF METALS
(2022)
Article
Materials Science, Multidisciplinary
Bart Weber, Julien Scheibert, Maarten P. de Boer, Ali Dhinojwala
Summary: Adhesion and friction between solids in ambient air play important roles in applications such as precision positioning and traction of tires. The roughness of solid interfaces, material parameters, sliding velocity, and normal load all contribute to adhesion and friction, leading to diverse phenomena. Recent advances have highlighted the importance of real contact area for both soft and hard materials, as well as the significance of rate-state-friction models in explaining the transition from stick-slip to steady sliding for hard contacts. However, there are still open experimental challenges regarding friction and adhesion of dry multi-contact interfaces.
Article
Materials Science, Composites
Kyle P. Schneider, Michael E. McHenry, Maarten P. de Boer
Summary: Metal Amorphous Nanocomposite (MANC) materials have low losses at high magnetic switching frequency, allowing for high power density motors with increased rotational speed. However, MANCs are brittle despite their high strength. In this study, a promising MANC alloy is tested in tension and failure is observed through high-speed photography. By developing a method to prepare laminated MANC and epoxy layers, the stacking of an epoxy-impregnated tape-wound core is simulated. Tensile tests are conducted on single layer ribbon and multiple layer stacks, showing an increasing Weibull modulus with more layers, and a k-failure model predicts the failure distribution of the laminated stacks.
JOURNAL OF COMPOSITE MATERIALS
(2023)
Article
Chemistry, Physical
Kyle P. Schneider, Yuval L. Krimer, Satoru Simizu, Maarten P. de Boer, Michael E. McHenry
Summary: Improvement of the (Fe70Ni30)(80)B14Nb4Si2 alloy is sought through substitution of Co for Fe and/or Ni. Fifteen alloys in the ((FexNiyCo(100-x-y))(80)B14Nb4Si2 alloy system are fabricated and analyzed for various properties relating to their soft magnetic performance. The most important properties studied here are Bsat, Ht, lambda(s), and Tc.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Engineering, Electrical & Electronic
Zhiqiang Wang, Siyang Dai, Yao Zhao, Guofeng Li, Bing Ji, Volker Pickert, Bowen Gu, Shuai Ding
Summary: This paper proposes a lumped-charge model for IEGT single chip, considering the effect of carrier injection enhancement in the emitter. The parasitic inductance of the parallel branches in PP-IEGT is extracted using Ansys simulation, and the validity of Ansys simulation is verified. Furthermore, the switching inconsistency is evaluated by combining the electrical model and the effect of mutual inductance, and it is found that mutual inductance is an important factor influencing electrical parameter distribution.
MICROELECTRONICS RELIABILITY
(2024)
Article
Engineering, Electrical & Electronic
Sankha Subhra Ghosh, Surajit Chattopadhyay, Arabinda Das, Nageswara Rao Medikondu, Abdulkarem H. M. Almawgani, Adam R. H. Alhawari, Sudipta Das
Summary: This article describes a method for identifying the IGBT switch breakdown failure in a 3-phase, 3-level Voltage Source Converter linked to the photovoltaic grid. Comparative learning has been used to detect the specific parameter suitable for the detection of the failure.
MICROELECTRONICS RELIABILITY
(2024)
Article
Engineering, Electrical & Electronic
Milad Khajehvand, Henri Seppanen, Panthea Sepehrband
Summary: Using SEM/EDX analysis, microscale fracture at the bond-pad is detected during the wedge bonding process of Cu wire to a Cu or Al substrate. It is observed that the fracture of the bond leads to the formation of a bulge on the wire and a cavity in the substrate, causing fracture in the original substrate. 3D optical profiler reveals that the depth, radius, and surface area of the cavity increase with bond time for a constant bond force and power. These metrics are suggested as new factors for optimizing the wedge bonding process. The optimal bonding parameters should maximize the cavity's surface area (related to bond's pull force) while minimizing the cavity's depth relative to the substrate's thickness to avoid substrate damage. Furthermore, Molecular Dynamics simulations propose a potential plastic deformation mechanism for bond-pad damage, suggesting the benefits of using a small-grain-sized substrate, low transducer's vibration amplitude, and high transducer's frequency to minimize the cavity's depth.
MICROELECTRONICS RELIABILITY
(2024)
