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Mid-wave to near-IR optoelectronic properties and epsilon-near-zero behavior in indium-doped cadmium oxide

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Physical Review Materials 2021年第3期5卷 035202-035202页

作者： Angela Cleri John Tomko Kathleen Quiambao-Tomko Mario V. Imperatore Yanglin Zhu J. Ryan Nolen Joshua Nordlander Joshua D. Caldwell Zhiqiang Mao Noel C. Giebink Kyle P. Kelley Evan L. Runnerstrom Patrick E. Hopkins Jon-Paul Maria Penn State University Department of Materials Science and Engineering University Park Pennsylvania 16802 USA University of Virginia Department of Materials Science and Engineering Charlottesville Virginia 22904 USA Penn State University Department of Electrical Engineering University Park Pennsylvania 16802 USA Penn State University Department of Physics University Park Pennsylvania 16802 USA Vanderbilt University Interdisciplinary Materials Science Program Nashville Tennessee 37235 USA Oak Ridge National Laboratory Center for Nanophase Materials Science Oak Ridge Tennessee 37830 USA Army Research Office DEVCOM US Army Research Laboratory Research Triangle Park North Carolina 27709 USA University of Virginia Department of Mechanical and Aerospace Engineering Charlottesville Virginia 22904 USA University of Virginia Department of Physics Charlottesville Virginia 22904 USA

Indium-doped cadmium oxide (In:CdO) thin films exhibit tunable epsilon-near-zero (ENZ) modal frequencies across a wide spectral range, bridging the mid-wave and near-infrared (IR). In:CdO thin films are prepared by reactive cosputtering from metallic Cd and In targets using high-power impulse magnetron sputtering (HiPIMS) and radio frequency sputtering, respectively. Using this approach, CdO thin films with carrier concentrations ranging from 2.3×1019 to 4.0×1020cm–3 and mobilities ranging from 300 to 400cm2/Vs are readily achieved. UV-VIS absorption spectra are used to measure optical bandgap, revealing a Burstein-Moss shift of 0.58 eV across the doping range investigated. Optical measurements demonstrate the tunability of near-perfect plasmonic ENZ absorption across the mid-wave and into the near-IR spectral ranges by controlling the carrier concentration through doping, while tuning the film thickness for impedance matching. In comparison to other dopants that can be introduced to HiPIMS-deposited CdO, In offers the largest range of carrier concentrations while maintaining high mobility, thus allowing for the widest accessibility of the IR spectrum of a single plasmonic material grown by sputtering.

关键词： Plasmonics Reflectivity X-ray diffraction

Tuning cooperative behavior in games with nonlinear opinion dynamics

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arXiv 2021年

作者： Park, Shinkyu Bizyaeva, Anastasia Kawakatsu, Mari Franci, Alessio Leonard, Naomi Ehrich Computer Electrical and Mathematical Science and Engineering Division Thuwal23955-6900 Saudi Arabia Department of Mechanical and Aerospace Engineering Princeton University PrincetonNJ08544 United States Program in Applied and Computational Mathematics Princeton University PrincetonNJ08544 United States Mathematics Department National Autonomous University of Mexico Mexico City04510 Mexico

We examine the tuning of cooperative behavior in repeated multi-agent games using an analytically tractable, continuous-time, nonlinear model of opinion dynamics. Each modeled agent updates its real-valued opinion about each available strategy in response to payoffs and other agent opinions, as observed over a network. We show how the model provides a principled and systematic means to investigate behavior of agents that select strategies using rationality and reciprocity, key features of human decision-making in social dilemmas. For two-strategy games, we use bifurcation analysis to prove conditions for the bistability of two equilibria and conditions for the first (second) equilibrium to reflect all agents favoring the first (second) strategy. We prove how model parameters, e.g., level of attention to opinions of others (reciprocity), network structure, and payoffs, influence dynamics and, notably, the size of the region of attraction to each stable equilibrium. We provide insights by examining the tuning of the bistability of mutual cooperation and mutual defection and their regions of attraction for the repeated prisoner's dilemma and the repeated multi-agent public goods game. Our results generalize to games with more strategies, heterogeneity, and additional feedback dynamics, such as those designed to elicit cooperation. Copyright © 2021, The Authors. All rights reserved.

关键词： Bifurcation (mathematics)

CoHaptics: Development of human-robot collaborative system with forearm-worn haptic display to increase safety in future factories

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arXiv 2021年

作者： Cabrera, Miguel Altamirano Heredia, Juan Tirado, Jonathan Panov, Vladislav Hagos, Fikre Tsetserukou, Dzmitry Bolshoy Boulevard 30 bld. 1 Moscow121205 Russia The Maersk Mc-Kinney Moller Institute The University of Southern Denmark Odense Denmark PMAR Robotics Group Department of Mechanical Energy Management and Transportation Engineering University of Genoa GE Genoa16145 Italy

Complex tasks require human collaboration since robots do not have enough dexterity. However, robots are still used as instruments and not as collaborative systems. We are introducing a framework to ensure safety in a human-robot collaborative environment. The system is composed of a haptic feedback display, low-cost wearable mocap, and a new collision avoidance algorithm based on the Artificial Potential Fields (APF). Wearable optical motion capturing system enables tracking the human hand position with high accuracy and low latency on large working areas. This study evaluates whether haptic feedback improves safety in human-robot collaboration. Three experiments were carried out to evaluate the performance of the proposed system. The first one evaluated human responses to the haptic device during interaction with the Robot Tool Center Point (TCP). The second experiment analyzed human-robot behavior during an imminent collision. The third experiment evaluated the system in a collaborative activity in a shared working environment. This study had shown that when haptic feedback in the control loop was included, the safe distance (minimum robot-obstacle distance) increased by 4.1 cm from 12.39 cm to 16.55 cm, and the robot's path, when the collision avoidance algorithm was activated, was reduced by 81%. © 2021, CC BY.

关键词： Collision avoidance

Concept development of exercise-to-power: The Green&Healthy power concept

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Cleaner Energy Systems 2024年 8卷

作者： Herwin Saito Schultz Carlos Eduardo Keutenedjian Mady Monica Carvalho Graduate Program in Mechanical Engineering Federal University of Paraíba. João Pessoa Brazil Institute of Energy and Environment University of São Paulo São Paulo Brazil Department of Renewable Energy Engineering Federal University of Paraíba. João Pessoa Brazil

Energy harvesting systems can capture and convert small amounts of energy from various natural sources, contributing to offsetting the growing global energy challenges without incurring the depletion of additional energy resources. Human kinetic energy can be obtained from physical exercise - in indoor cycling, the athlete's metabolic energy converts into heat, enthalpy (to the environment), and work. This study reports on the concept development of the Green&Healthy Power system, an energy harvesting system that collects energy from physical activities. A case study based on an indoor bike generator as a conceptual innovation is presented. The user can select the intensity of effort in which the exercise occurs to produce electricity. Using situations based on literature results, the gains are evaluated by measuring aerobic endurance. The user is informed about the health benefits of the exercise (traditional indices), the energy produced, and the greenhouse gas emissions avoided. This study also reviews some aspects of precedent practices, highlighting the concept's challenging characteristics and setting out the initial formulation of the Green&Healthy Power system. This contribution defines research, development, and demonstration priorities for new ideas and technologies to improve energy efficiency and reduce the final consumption of primary energy. As results of the study case, initial figures indicate that 1000 people performing 20 min of activities on the energy harvesting system three times a week can avoid annual emissions of 180 kg CO 2 and produce 800 kWh/year of electricity, resulting in savings of R$ 800/year. Brazil has a population of 200 million inhabitants and if 1 % of the population carried out this activity, electricity generation could reach up to 1.6 TWh/month (= 19.2 TWh/year), representing 3.4 % of electricity flows within the Brazilian electricity matrix.

关键词： Harvest energy Electricity generation Physical exercises Improvement of public health Life cycle assessment ADP Adenosine Diphosphate ATP Adenosine Triphosphate EHF Energy Harvest Farm EHS Energy Harvesting Systems GHG Greenhouse Gases

An energy efficiency evaluation method for parallel robots based on the kinetic energy change rate

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Science China(Technological Sciences) 2019年第6期62卷 1035-1044页

作者： LIU XinJun BI WeiYao XIE FuGui The State Key Laboratory of Tribology & Tsinghua University (DME)-Siemens Joint Research Center for Advanced Robotics Department of Mechanical Engineering (DME) Tsinghua University Beijing 100084 China Beijing Key Lab of Precision/Ultra-precision Manufacturing Equipments and Control Tsinghua University Beijing 100084 China

Benefit from the high payload-to-weight ratio, parallel robots are expected to have a high potential for energy savings. However,it is a challenging issue to evaluate the energy efficiency of parallel robots with a quantitative method. Quantitative energy efficiency evaluation methods include energy efficiency evaluation models and indices which mathematically describe the relationship between energy consumers in models and design variables of robots, such as geometry, mass and inertia *** the structural features of parallel robots, the chains and the end effectors are identified as two separated energy consumers. Besides, the chains in parallel robots are identified as a transmission system which transfers energy from drives to the end effectors. On this basis, an energy efficiency evaluation model considering the change rate of kinetic energy stored in chains is built. The kinetic energy change rate of chains is influenced by design variables of robots as well as motion of the end *** order to give a quantitative description of energy efficiency performance of parallel robots, indices considering arbitrary velocity vector of the end effector are proposed. The evaluation method is suitable for all kinds of parallel robots with various motion conditions. Furthermore, the method can be used to optimize machining parameters and guide the design of energyefficient machines.

关键词： energy efficiency evaluation parallel robots kinetic energy power transmission

Towards precise pruning points detection using semantic-instance-aware plant models for grapevine winter pruning automation

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arXiv 2021年

作者： Fernandes, Miguel Scaldaferri, Antonello Guadagna, Paolo Fiameni, Giuseppe Teng, Tao Gatti, Matteo Poni, Stefano Semini, Claudio Caldwell, Darwin Chen, Fei Active Perception and Robot Interactive Learning Laboratory Department of Advanced Robotics Istituto Italiano di Tecnologia Via Morego 30 Genova16163 Italy Department of Informatics Bioengineering Robotics and System Engineering Università di Genoa Viale Causa 13 Genova16145 Italy Department of Sustainable Crop Production Università Cattolica del Sacro Cuore Via Emilia Parmense 84 Piacenza29122 Italy Italy lab Istituto Italiano di Tecnologia Via Morego 30 Genova16163 Italy Department of Mechanical and Automation Engineering T-Stone Robotics Institute The Chinese University of Hong Kong Chung Chi Rd Ma Liu Shui Hong Kong

Grapevine winter pruning is a complex task, that requires skilled workers to execute it correctly. The complexity makes it time consuming. It is an operation that requires about 80-120 hours per hectare annually, making an automated robotic system that helps in speeding up the process a crucial tool in large-size vineyards. We will describe (a) a novel expert annotated dataset for grapevine segmentation, (b) a state of the art neural network implementation and (c) generation of pruning points following agronomic rules, leveraging the simplified structure of the plant. With this approach, we are able to generate a set of pruning points on the canes, paving the way towards a correct automation of grapevine winter pruning. © 2021, CC BY.

关键词： Automation

Efficient Path Planning in Narrow Passages for Robots with Ellipsoidal Components

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arXiv 2021年

作者： Ruan, Sipu Poblete, Karen L. Wu, Hongtao Ma, Qianli Chirikjian, Gregory S. Department of Mechanical Engineering National University of Singapore Singapore Laboratory for Computational Sensing and Robotics Johns Hopkins University BaltimoreMD21218 United States Epic Systems VeronaWI53593 United States Motional Inc. PittsburghPA15207 United States

Path planning has long been one of the major research areas in robotics, with PRM and RRT being two of the most effective classes of planners. Though generally very efficient, these sampling-based planners can become computationally expensive in the important case of "narrow passages". This paper develops a path planning paradigm specifically formulated for narrow passage problems. The core is based on planning for rigid-body robots encapsulated by unions of ellipsoids. Each environmental feature is represented geometrically using a strictly convex body with a C1 boundary (e.g., superquadric). The main benefit of doing this is that configuration-space obstacles can be parameterized explicitly in closed form, thereby allowing prior knowledge to be used to avoid sampling infeasible configurations. Then, by characterizing a tight volume bound for multiple ellipsoids, robot transitions involving rotations are guaranteed to be collision-free without needing to perform traditional collision detection. Furthermore, by combining with a stochastic sampling strategy, the proposed planning framework can be extended to solving higher dimensional problems in which the robot has a moving base and articulated appendages. Benchmark results show that the proposed framework often outperforms the sampling-based planners in terms of computational time and success rate in finding a path through narrow corridors for both single-body robots and those with higher dimensional configuration spaces. Physical experiments using the proposed framework are further demonstrated on a humanoid robot that walks in several cluttered environments with narrow passages. © 2021, CC BY-NC-ND.

关键词： Motion planning

Application of qualitative and quantitative methods of analysis in designing research into the vibrations of an oscillator forced by a random series of impulses

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Application of qualitative and quantitative methods of analy...

作者： Ozga, Agnieszka AGH University of Science and Technology Faculty of Mechanical Engineering and Robotics Department of Mechanics and Vibroacoustics Al. Mickiewicza 30 Krakow30-059 Poland

The paper describes the changes that take place in an oscillator with damping, whose vibrations were forced by a random series of impulses. The idea of application of the qualitative and quantitative methods of analysis for solving the problems that occur in mechanical engineering has been presented. Qualitative methods were used to design simulation and experimental studies verifying the stochastic model. Quantitative methods were applied to solve a reverse problem which consisted in finding the distributions of the values of impulses forcing the vibrations of the oscillator. © 2019, Springer Nature Switzerland AG.

关键词： Inverse problems

Design and control of a highly redundant rigid–flexible coupling robot to assist the COVID-19 oropharyngeal-swab sampling

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arXiv 2021年

作者： Hu, Yingbai Li, Jian Chen, Yongquan Wang, Qiwen Chi, Chuliang Zhang, Heng Gao, Qing Lan, Yuanmin Li, Zheng Mu, Zonggao Sun, Zhenglong Knoll, Alois Robotics and Intelligent Manufacturing & School of Science and Engineering The Chinese University of Hong Kong Shenzhen518172 China Shenzhen Institute of Artificial Intelligence and Robotics for Society 518129 China Chair of Robotics Artificial Intelligence and Real-time Systems Technische Universität München München85748 Germany Department of surgery Chow Yuk Ho Technology Centre for Innovative Medicine The Chinese University of Hong Kong Hong Kong School of Mechanical Engineering Shandong University of Technology Zibo255000 China Longgang District People’s Hospital of Shenzhen 518172 China

The outbreak of novel coronavirus pneumonia (COVID-19) has caused mortality and morbidity worldwide. Oropharyngeal-swab (OP-swab) sampling is widely used for the diagnosis of COVID-19 in the world. To avoid the clinical staff from being affected by the virus, we developed a 9-degree-of-freedom (DOF) rigid–flexible coupling (RFC) robot to assist the COVID-19 OP-swab sampling. This robot is composed of a visual system, UR5 robot arm, micro-pneumatic actuator and force-sensing system. The robot is expected to reduce risk and free up the clinical staff from the long-term repetitive sampling work. Compared with a rigid sampling robot, the developed force-sensing RFC robot can facilitate OP-swab sampling procedures in a safer and softer way. In addition, a varying-parameter zeroing neural network-based optimization method is also proposed for motion planning of the 9-DOF redundant manipulator. The developed robot system is validated by OP-swab sampling on both oral cavity phantoms and volunteers. Copyright © 2021, The Authors. All rights reserved.

关键词： Motion planning