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Silicon Photonics XVIII 2023

作者： Olorunsola, Oluwatobi Said, Abdulla Ojo, Solomon Stanchu, Hryhorii Abernathy, Grey Amoah, Sylvester Saha, Samir Wangila, Emmanuel Grant, Joshua Acharya, Sudip Jheng, Yue-Tong Chang, Guo-En Li, Baohua Salamo, Gregory Yu, Shui-Qing Du, Wei Department of Electrical Engineering University of Arkansas FayettevilleAR72701 United States Material Science and Engineering Program University of Arkansas FayettevilleAR72701 United States Institute for Nanoscience and Engineering University of Arkansas FayettevilleAR72701 United States Department of Physics University of Arkansas FayettevilleAR72701 United States Department of Mechanical Engineering National Chun Cheng University Chiayi County62101 Taiwan Arktonics LLC 1339 South Pinnacle Drive FayettevilleAR72701 United States

ISBN: (纸本)9781510659575

As one of two mainstream platforms, photonics integrated circuits (PICs) on Si photonics platform benefits from the mature complementary metal-oxide-semiconductor (CMOS) manufacturing capabilities and allows for the processing of Si-based PICs with ultra-high volume and low cost. Recent studies of SiGeSn materials, which yield true direct bandgap with sufficient Sn incorporation, hold great promise for PICs featuring scalable, cost-effective, and power-efficient. While the exciting developments in bulk devices including lasers, light emitting diodes (LEDs), and photodetector were reported, the quantum wells (QWs) structure and devices have been investigated targeting the dramatically improved and/or novel device performance via variety of quantum confinement effects. In this work, we report the recent progress on SiGeSn QW development. Particularly, the study of MQW laser is presented. Devices with higher optical confinement factors exhibit clear lasing confirmed by the threshold characteristic and the emission spectra below and above threshold. Only spontaneous emission was observed with the thinner cap layer samples. On the other hand, samples with thicker cap layers of 250 and 290 nm exhibit clear lasing at 77 K with thresholds of 214 and 664 kW/cm2, respectively. These promising results establish the guidance for the device design and pave the way for the SiGeSn QW devices towards future high-performance PICs on Si platform. © 2023 SPIE.

关键词： Timing circuits

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Reconfiguring Surface Acoustic Wave Microfluidics via In Situ Control of Elastic Wave Polarization

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Physical Review Letters 2025年第3期134卷 037002-037002页

作者： Yu Gao (郜煜) Thomas Voglhuber-Brunnmaier Yuekang Li Leyla Akh Nicholas H. Patino Apresio Kefin Fajrial Massimo Ruzzene Bernhard Jakoby Xiaoyun Ding Paul M. Rady Department of Mechanical Engineering University of Colorado Boulder Colorado 80309 USA Institute for Microelectronics and Microsensors Johannes Kepler University Linz Austria Biomedical Engineering Program University of Colorado Boulder Colorado 80309 USA Materials Science and Engineering Program University of Colorado Boulder Colorado 80309 USA BioFrontiers Institute University of Colorado Boulder Colorado 80309 USA

We demonstrate in situ control of the elastic wave polarization in a surface acoustic wave (SAW). It allows us to create highly reconfigurable SAW microfluidics that can be switched on demand between the acoustohydrodynamic (AHD) regime and electrohydrodynamic (EHD) regime for manipulating particles and cells. The control of wave polarization comes from our experimental and theoretical identification of an unexpected shear-horizontal (SH) wave mode in a conventional Rayleigh (R) wave design, which is stereotyped to excite only vertically polarized Rayleigh SAWs. The SH wave mode is predominantly horizontally polarized and can be selectively excited to propagate in the same direction as the Rayleigh SAW. Such a selective wave generation between the SH mode and R mode allows for reconfiguration between AHD and EHD regimes that leads to unprecedented colloidal patterns and assembly dynamics. Such a reconfiguration of the particle manipulation mechanism can be explained by the controllable competition or synergism between the coexisting acoustic and electric fields. Remarkably, in the EHD regime, a virtual zero-boundary electric quadrupole is created, and a novel colloidal diamond-shaped assembly is observed in this piezoelectric-quadrupole trap, which was rarely reported in acoustic or electric microfluidics. The presented in situ control of polarization revolutionizes our understanding of SAW and acoustofluidics, expands its potential by assuming the advantages of AHD and EHD on demand, and inspires new strategies in micro- and nanoscale manufacturing and manipulation, with applications beyond fundamental scientific interest.

关键词： Microfluidics

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Enhancing PV solar panel efficiency through integration with a passive Multi-layered PCMs cooling system: A numerical study

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International Journal of Thermofluids 2024年 23卷

作者： Sheikh, Yahya Jasim, Muhammad Qasim, Muhammad Qaisieh, Alaa Hamdan, Mohammad O. Abed, Farid Materials Science and Engineering Program American University of Sharjah Sharjah United Arab Emirates Department of Mechanical Engineering American University of Sharjah Sharjah United Arab Emirates Department of Chemical and Biological Engineering American University of Sharjah Sharjah United Arab Emirates Civil Engineering Department American University of Sharjah Sharjah United Arab Emirates

Photovoltaic (PV) solar cells are at the forefront of sustainable electricity generation technologies, yet they exhibit relatively low efficiency. Typically, less than 20 % of the solar energy absorbed is converted into electrical energy, with the remainder converts into heat. This heat increases the PV panel's operating temperature, negatively impacting its efficiency and life expectancy. To mitigate this, a novel approach using multi-layered phase change materials (PCMs) has been examined in this study. The approach involves integrating organic PCMs (OPCMs) with metallic PCMs (MPCMs), enhancing PV panel cooling efficiency by attaching the multi-layer PCM to the panel's rear. This study, employing ANSYS FLUENT software's solidification and melting model, explores the impact of multi PCM layers thickness and total multi layers thickness on PV cell temperature and electrical efficiency. The analysis reveals that a multi-layered PCMs configuration with a thickness ratio of 15:85 between MPCM (CERROLOW-117® alloy) and OPCM (RT44) significantly decreases temperature rise in PV cells, resulting in a temperature drop of 59.6 °C. This improvement boosts PV panel performance by an average of 35.8 % compared to panels lacking cooling systems during peak sun hours under hot climate conditions characterized by ambient temperatures of 40 °C and high solar radiation exceeding 1000 W/m². This suggests that a carefully optimized PCM layering approach could markedly improve PV system efficiency, offering a practical solution to the overheating problem and extending the operational life of PV installations. © 2024 The Author(s)

关键词： Phase change materials

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Modeling and Control of Inertia Wheel Pendulum System with LQR and PID control

Modeling and Control of Inertia Wheel Pendulum System with L...

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2021 International Seminar on Intelligent Technology and Its Application, ISITIA 2021

作者： Hidayati, Alfiana Nur Wasiwitono, Unggul Institut Teknologi Sepuluh Nopember Postgraduate Program of Mechanical Engineering Surabaya Indonesia Institut Teknologi Sepuluh Nopember Department of Mechanical Engineering Surabaya Indonesia

ISBN: (纸本)9781665428477

This study presents an analysis, control, and comparison of controllers used to stabilize the IWP with the help of the torque generated by a wheel driven by a DC motor. The dynamics of the IWP with the proportional integral derivative (PID) control and linear quadratic regulator (LQR) control are explored. The effect of actuator saturation on control performance is also studied. Controller performance is evaluated through simulation by using the nonlinear model developed in Simscape Multibody. The system can always return to equilibrium with any initial angle, but as the initial angle increases, a higher input voltage is required. In the saturated case, the system can only return to equilibrium with a maximum initial angle of 14.5 degrees. The LQR control has less overshoot but takes a longer time to return to the equilibrium point. © 2021 IEEE.

关键词： DC motors

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Erosion-corrosion resistance of Mo-Ti- and Ni-Cr-Mo-alloyed medium-carbon martensitic steels: a critical analysis of synergistic effect of erosion and corrosion

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Journal of Iron and Steel Research International 2022年第8期29卷 1299-1311页

作者： De-fa Li Hang-yu Dong Cheng-yang Hu Kai-ming Wu Serhii Yershov Oleg Isayev School of Mechanical and Vehicle Engineering West Anhui UniversityLuan 237012AnhuiChina The State Key Laboratory of Refractories and Metallurgy Hubei Province Key Laboratory of Systems Science on Metallurgical ProcessingInternational Research Institute for Steel TechnologyWuhan University of Science and TechnologyWuhan 430081HubeiChina Laboratory for Excellence in Advanced Steel Research Materials Science and Engineering ProgramDepartment of MetallurgicalMaterials and Biomedical EngineeringUniversity of Texas at El PasoEl PasoTX 79968USA

Grain refinement renders Mo-Ti-alloyed medium-carbon martensitic steel to exhibit high hardness,high strength,and good toughness,but the erosion-corrosion resistance of steel in a corrosive slurry environment is not ***-Ti-alloyed medium-carbon martensitic steel is compared with Ni-Cr-Mo-alloyed medium-carbon martensitic steel,and the erosion-corrosion resistance of those two steels under impingement by NaCl solution with gravels has been *** components,pure-corrosion rate,pure-erosion rate,and synergistic effect of erosion and corrosion(SEEC)of erosion-corrosion rate,were *** pure-corrosion and pure-erosion rates of Mo-Ti-alloyed steel were higher than those of Ni-Cr-Mo-alloyed one;however,its erosion-corrosion rate was relatively lower because of a weak *** plastic deformation and work hardening due to gravel impingement were the essential reason for SEEC,which could be reduced by grain refinement,and consequently,Mo-Ti-alloyed steel with finer grains had better erosion-corrosion *** refinement could be an effective way to improve the erosion-corrosion resistance of martensitic steels.

关键词： Grain refinement Mo-Ti alloying Ni-Cr-Mo alloying Martensite Erosion-corrosion

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Epilayer on NEAT Grown GaN Schottky Diodes for Radiation Detection

Epilayer on NEAT Grown GaN Schottky Diodes for Radiation Det...

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2023 Transactions of the American Nuclear Society Annual Meeting and Technology Expo, ANS 2023

作者： Remy, Jarod Zhang, Yuxuan Talesara, Vishank Zhao, Hongping Lu, Wu Hashimoto, Tadao Cao, Lei R. Nuclear Engineering Program Department of Mechanical and Aerospace Engineering 281 W. Lane Ave. ColumbusOH43210 United States Department of Electrical and Computer Engineering 281 W. Lane Ave ColumbusOH43210 United States Department of Material Science and Engineering The Ohio State University 281 W. Lane Ave ColumbusOH43210 United States SixPoint Materials Inc 37 Industrial Way STE 106 BuelltonCA United States

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Multi-Agent 3D Map Reconstruction and Change Detection in Microgravity with Free-Flying Robots 74

Multi-Agent 3D Map Reconstruction and Change Detection in Mi...

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74th International Astronautical Congress, IAC 2023

作者： Dinkel, Holly Di, Julia Santos, Jamie Albee, Keenan Borges, Paulo Moreira, Marina Alexandrov, Oleg Coltin, Brian Smith, Trey Department of Aerospace Engineering The University of Illinois Urbana-Champaign UrbanaIL United States Department of Mechanical Engineering Stanford University StanfordCA United States Department of Physics Chalmers University of Technology Gothenburg Sweden Maritime and Multi-Agent Autonomy Group The Jet Propulsion Laboratory California Institute of Technology PasadenaCA United States Robotics and Autonomous Systems Group CSIRO Data61 BrisbaneQLD Australia Intelligent Robotics Group The NASA Ames Research Center Moffett FieldCA United States

Assistive free-flyer robots autonomously caring for future crewed outposts-such as NASA's Astrobee robots on the International Space Station (ISS)-must be able to detect day-to-day interior changes to track inventory, detect and diagnose faults, and monitor the outpost status. This work presents a framework for multi-agent cooperative mapping and change detection to enable robotic maintenance of space outposts. One agent is used to reconstruct a 3D model of the environment from sequences of images and corresponding depth information. Another agent is used to periodically scan the environment for inconsistencies against the 3D model. Change detection is validated after completing the surveys using real image and pose data collected by Astrobee robots in a ground testing environment and from microgravity aboard the ISS. This work outlines the objectives, requirements, and algorithmic modules for the multi-agent reconstruction system, including recommendations for its use by assistive free-flyers aboard future microgravity outposts. Copyright © 2023 by the International Astronautical Federation (IAF). All rights reserved.

关键词： 3D Reconstruction Artemis Change Detection Mapping Microgravity robotics

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Renderable Street View Map-Based Localization: Leveraging 3D Gaussian Splatting for Street-Level Positioning

Renderable Street View Map-Based Localization: Leveraging 3D...

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IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)

作者： Howoong Jun Hyeonwoo Yu Songhwai Oh Artificial Intelligence (IPAI) Seoul National University and Automation and Systems Research Institute (ASRI) and Sequor Robotics Inc. Seoul Korea Republic of Department of Intelligent Robotics & Mechanical Engineering Sungkyunkwan University (SKKU) Suwon-si Korea Republic of Department of Electrical and Computer Engineering (ECE) & Interdisciplinary Program in Artificial Intelligence (IPAI) Seoul National University and Automation and Systems Research Institute (ASRI) and Sequor Robotics Inc. Seoul Korea Republic of

ISBN: (数字)9798350377705

ISBN: (纸本)9798350377712

In this paper, we introduce a new method that first utilizes 3D Gaussian splatting in street-level localization problem. Robust localization with street-level real-world images such as street view is a major issue for autonomous vehicle, augmented reality (AR) navigation, and outdoor mobile robots. The objective is to determine the position and orientation of a query image that matches a street view database composed of RGB images. However, given the limited information available in the street view images, accurately determining the location solely based on this data presents a significant challenge. To address this challenge, we propose a novel method called renderable street view map-based localization (RSM-Loc). This approach enhances the localization process by augmenting 2D street view images into a renderable 3D map using 3D Gaussian splatting, to resolve street-level localization problems. Upon receiving a query RGB image without geometry information, the proposed method renders 2D images from a pre-made renderable map and compares image pose similarities between the rendered images and the query image. Through iterations of this process, the proposed method eventually estimates the pose of the given query image. The experimental results demonstrate that RSM-Loc outperforms the baselines with neural-field-based localization. Additionally, we conduct deep analysis on the proposed method to show that our method can serve as a new concept for the street-level localization problem.

关键词： Location awareness Visualization Matched filters Three-dimensional displays Image resolution Navigation Noise measurement Mobile robots Intelligent robots Image reconstruction

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A Predefined-Time Convergent and Noise-Tolerant Zeroing Neural Network Model for Time Variant Quadratic programming With Application to Robot Motion Planning

arXiv

引用

arXiv 2024年

作者： Yang, Yi Wang, Xuchen Voyles, Richard M. Ma, Xin The Multi-Scale Medical Robotics Center The Department of Mechanical and Automation Engineering The Chinese University of Hong Kong 999077 Hong Kong The School of Engineering Technology Purdue University West LafayetteIN47907 United States

This paper develops a predefined-time convergent and noise-tolerant fractional-order zeroing neural network (PTC-NT-FOZNN) model, innovatively engineered to tackle time-variant quadratic programming (TVQP) challenges. The PTC-NT-FOZNN, stemming from a novel iteration within the variable-gain ZNN spectrum, known as FOZNNs, features diminishing gains over time and marries noise resistance with predefined-time convergence, making it ideal for energy-efficient robotic motion planning tasks. The PTC-NT-FOZNN enhances traditional ZNN models by incorporating a newly developed activation function that promotes optimal convergence irrespective of the model’s order. When evaluated against six established ZNNs, the PTC-NT-FOZNN, with parameters 0 © 2024, CC BY.

关键词： Robot programming

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Assessment of Contact Parameters of Semi-Elliptical Soft Fingertips for Anthropomorphic Robotic Grippers 2

Assessment of Contact Parameters of Semi-Elliptical Soft Fin...

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2nd International Conference on Technological Advancements in Computational Sciences, ICTACS 2022

作者： Ramachandran, Balaji Yuvarai, S. Bharat Kumar, M.R. Raj, Samudrala Sahan Babu, T Sarath Kannan, M. NoobTron Private Limited Chitlapakkam Tamilnadu Chennai India Easwari Engineering College Department of Robotics and Automation Tamilnadu Chennai India Sri Sai Ram Engineering College Department of Electronic and Instrumentation and Engineering Tamilnadu Chennai India Guru Nanak Institutions Campus Telangana Ibrahimpatnam India Mother Theresa Institute of Engineering and Technology Palamaner Chittoor India Kcg College of Technology OMR Karapakkam Department of Mechanical Engineering Tamilnadu Chennai India

ISBN: (数字)9781665476577

ISBN: (纸本)9781665476577

Robotic and artificial hands use soft fingers as fingertips for better stability in grasping and manipulation. Soft fingertips are used it increases the capability to make steady then encircling grips by deforming throughout connection and applying a large interstellar of mechanical loads then displacement of the rigid target objects. The study of contact mechanics for the soft finger in previous research has been carried out on the hemispherical and cylindrical structures whereas this study concentrates on the use of a semi-elliptical structure, which represents more realistic soft fingertips. This work presents an experimental comparison between a hemispherical, semi-elliptical, and cylindrical structure to be used as a soft fingertip that is this work compares the contact parameters of a soft hemispherical finger-tip, semi-elliptical fingertip, and cylindrical fingertip pressed against a flat, convex, and a concave profile. The analysis of soft fingertips on various types of profiles plays the main role in the modeling of anthropomorphic robotic fingertips. From this study, the semi-elliptical fingertip can be used for both precision and power grasp that depends upon the target profile. © 2022 IEEE.

关键词： Grippers

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