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Excitation of the abdominal ganglion affects the electrophysiological activity of indirect flight muscles of the honeybee Apis mellifera

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Insect Science 2024年第4期31卷 1187-1199页

作者： Haojia Ding Shaoze Yan State Key Laboratory of Tribology in Advanced Equipment(SKLT) Division of Intelligent and Biomechanical SystemsDepartment of Mechanical EngineeringTsinghua UniversityBeijingChina

Our understanding of the nervous tissues that affect the wing flapping of insects mainly focuses on the brain,but wing flapping is a rhythmic movement related to the central pattern generator in the ventral nerve *** verify whether the neural activity of the abdominal ganglion of the honeybee(Apis mellifera)affects the flapping-wing flight,we profiled the response characteristics of indirect flight muscles to abdominal ganglion ***,a change in the neural activity of ganglion 3 or ganglion 4 has a stronger effect on the electrophysiological activity of indirect flight muscles than that of ganglion *** electrophysiological activity of vertical indirect flight muscles is affected more by the change in neural activity of the abdominal ganglion than that of lateral indirect flight ***,the change in neural activity of the abdominal ganglion mainly causes the change in the muscular activity of indirect wing muscles,but the activity patterns change relatively little and there is little change in the complicated *** work improves our understanding of the neuroregulatory mechanisms associated with the flapping-wing flight of honeybees.

关键词： abdominal ganglion electromyography flapping wing honeybee indirect flight muscle muscular activity

Development of wet adhesion of honeybee arolium incorporated polygonal structure with three-phase composite interfaces

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Friction 2024年第2期12卷 215-230页

作者： Lulu LIANG Jieliang ZHAO Qun NIU Li YU Xiangbing WU Wenzhong WANG Shaoze YAN Zhenglei YU School of mechanical engineering Beijing Institute of TechnologyBeijing 100081China Division of intelligent and Biomechanical systems State Key Laboratory of TribologyDepartment of Mechanical EngineeringTsinghua UniversityBeijing 100084China Key of Bionic engineering Ministry of EducationJilin UniversityChangchun 130022China

Inspired by the dynamic wet adhesive systems in nature,various artificial adhesive surfaces have been developed but still face different ***,the theoretical mechanics of wet adhesives has never been sufficiently ***,we develop a novel adhesive mechanism for governing wet adhesion and investigate the biological models of honeybee arolium for reproducing the natural wet adhesive ***-nano structures of honeybee arolium and arolium-prints were observed by Cryogenic scanning electron microscopy(Cryo-SEM),and the air pockets were found in the contact interface ***,the adhesive models with a three-phase composite interface(including air pockets,liquid secretion,and hexagonal frames of arolium),were formed to analyze the wet adhesion of honeybee *** results of theoretical calculations and experiments indicated an enhanced adhesive mechanism of the honeybee by liquid self-sucking effects and air-embolism *** these effects,normal and shear adhesion can be adjusted by controlling the proportion of liquid secretion and air pockets in the contact ***,the air-embolism effects contribute to the optimal coupling of smaller normal adhesion with greater shear adhesion,which is beneficial for the high stride frequency of *** works can provide a fresh perspective on the development of bio-inspired wet adhesive surfaces.

关键词： honeybee arolium air pockets wet adhesion a three-phase interface self-sucking effects air-embolism effects

Regularizing fuel-optimal multi-impulse trajectories

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Astrodynamics 2024年第1期8卷 97-119页

作者： Kenta Oshima department of mechanical systems engineering Hiroshima Institute of TechnologyHiroshima731-5193Japan

The regularization theory has successfully enabled the removal of gravitational singularities associated with celestial *** this study,regularizing techniques are merged into a multi-impulse trajectory design framework that requires delicate computations,particularly for a fuel minimization *** variables based on the Levi–Civita or Kustaanheimo–Stiefel transformations express instantaneous velocity changes in a gradient-based direct optimization *** formulation removes the adverse singularities associated with the null thrust impulses from the derivatives of an objective function in the fuel minimization *** favorite singularity-free property enables the accurate reduction of unnecessary impulses and the generation of necessary impulses for local optimal solutions in an automatic *** of fuel-optimal multi-impulse trajectories are presented,including novel transfer solutions between a near-rectilinear halo orbit and a distant retrograde orbit.

关键词： regularization trajectory optimization fuel minimization multi-impulse trajectory

Position-aware pushing and grasping synergy with deep reinforcement learning in clutter

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CAAI Transactions on Intelligence Technology 2024年第3期9卷 738-755页

作者： Min Zhao Guoyu Zuo Shuangyue Yu Daoxiong Gong Zihao Wang Ouattara Sie intelligent Robotics Laboratory Faculty of Information TechnologyBeijing University of TechnologyBeijingChina Beijing Key Laboratory of Computational Intelligence and intelligent systems BeijingChina Laboratory of Biomechatronics and intelligent Robotics(BIRO) Department of Mechanical and Aerospace EngineeringNorth Carolina State UniversityRaleighNorth CarolinaUSA

The positional information of objects is crucial to enable robots to perform grasping and pushing manipulations in *** effectively perform grasping and pushing manipu-lations,robots need to perceive the position information of objects,including the co-ordinates and spatial relationship between objects(e.g.,proximity,adjacency).The authors propose an end-to-end position-aware deep Q-learning framework to achieve efficient collaborative pushing and grasping in ***,a pair of conjugate pushing and grasping attention modules are proposed to capture the position information of objects and generate high-quality affordance maps of operating positions with features of pushing and grasping *** addition,the authors propose an object isolation metric and clutter metric based on instance segmentation to measure the spatial re-lationships between objects in cluttered *** further enhance the perception capacity of position information of the objects,the authors associate the change in the object isolation metric and clutter metric in cluttered environment before and after performing the action with reward function.A series of experiments are carried out in simulation and real-world which indicate that the method improves sample efficiency,task completion rate,grasping success rate and action efficiency compared to state-of-the-art end-to-end *** that the authors’system can be robustly applied to real-world use and extended to novel *** material is available at https://***/NhG\_k5v3NnM}{https://***/NhG\_k5v3NnM.

关键词： deep learning deep neural networks intelligent robots

Thermal noise-driven resonant sensors

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Microsystems & Nanoengineering 2024年第3期10卷 259-271页

作者： Yan Qiao Alaaeldin Elhady Mohamed Arabi Eihab Abdel-Rahman Wenming Zhang School of mechanical engineering Shanghai Jiao Tong UniversityShanghaiChina department of systems Design engineering University of WaterlooWaterlooONCanada

MEMS/NEMS resonant sensors hold promise for minute mass and force ***,one major challenge is that conventional externally driven sensors inevitably encounter undesired intrinsic noise,which imposes a fundamental limitation upon their signal-to-noise ratio(SNR)and,consequently,the ***,this restriction becomes increasingly pronounced as sensors shrink to the *** this work,we propose a counterintuitive paradigm shift that turns intrinsic thermal noise from an impediment to a constituent of the sensor by harvesting it as the driving force,obviating the need for external actuation and realizing‘noise-driven’*** sensors employ the dynamically amplified response to thermal noise at resonances for stimulus *** demonstrate that lightly damped and highly compliant nano-structures with high aspect ratios are promising candidates for this class of *** overcome the phase incoherence of the drive force,three noise-enabled quantitative sensing mechanisms are *** validated our sensor paradigm by experimental demonstrating noise-driven pressure and temperature ***-driven sensors offer a new opportunity for delivering practical NEMS sensors that can function at room temperature and under ambient pressure,and a development that suggests a path to cheaper,simpler,and low-power-consumption sensors.

关键词： noise resonant overcome

Generating synthetic as-built additive manufacturing surface topography using progressive growing generative adversarial networks

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Friction 2024年第6期12卷 1283-1298页

作者： Junhyeon SEO Prahalada RAO Bart RAEYMAEKERS department of mechanical engineering Virginia TechBlacksburgVA 24061USA Grado department of Industrial and systems engineering Virginia TechBlacksburgVA 24061USA

Numerically generating synthetic surface topography that closely resembles the features and characteristics of experimental surface topography measurements reduces the need to perform these intricate and costly ***,existing algorithms to numerically generated surface topography are not well-suited to create the specific characteristics and geometric features of as-built surfaces that result from laser powder bed fusion(LPBF),such as partially melted metal particles,porosity,laser scan lines,and ***,we present a method to generate synthetic as-built LPBF surface topography maps using a progressively growing generative adversarial *** qualitatively and quantitatively demonstrate good agreement between synthetic and experimental as-built LPBF surface topography maps using areal and deterministic surface topography parameters,radially averaged power spectral density,and material ratio *** ability to accurately generate synthetic as-built LPBF surface topography maps reduces the experimental burden of performing a large number of surface topography ***,it facilitates combining experimental measurements with synthetic surface topography maps to create large data-sets that facilitate,*** as-built surface topography to LPBF process parameters,or implementing digital surface twins to monitor complex end-use LPBF parts,amongst other applications.

关键词： additive manufacturing surface topography synthetic surface topography generative adversarial networks

Comment on “Ferroelectric composite-based piezoelectric energy harvester for self-powered detection of obstructive sleep”

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Journal of Materiomics 2024年第5期10卷 1144-1146页

作者： Alexander Tkach Olena Okhay CICECO-Aveiro Institute of Materials Department of Materials and Ceramic EngineeringUniversity of Aveiro3810-193AveiroPortugal TEMA-Centre for mechanical Technology and Automation Department of Mechanical EngineeringUniversity of Aveiro3810-193AveiroPortugal LASI-intelligent systems Associate Laboratory 4800-058GuimaraesPortugal

SrTi_(2)O_(5) particles were claimed by Panda et *** *** 2023;9:609 as a new lead-free ferroelectric material with orthorhombic symmetry and space group of Cmm2,being,therefore,employed as a base of piezoelectric energy ***,in this comment we express concerns regarding the presence of the piezoelectricity in the studied material and the interpretation of the structural,microstructural,and ferroelectric results in that publication as those associated with SrTi_(2)O_(5).We also note that the presented dielectric results are contradictory and that many important details are missing.

关键词： SrTiO_(3) Dielectric permittivity Ferroelectrics Piezoelectrics Energy harvesting

Flexible sensors with zero Poisson's ratio

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National Science Review 2024年第5期11卷 153-169页

作者： Xin Huang Tianzhao Bu Qingyang Zheng Shaoyu Liu Yangyang Li Han Fang Yuqi Qiu Bin Xie Zhouping Yin Hao Wu department of mechanical engineering Flexible Electronics Research Center State Key Laboratory of Intelligent Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and Technology department of Electronic Science and Technology School of Integrated CircuitsHuazhong University of Science and Technology

Flexible sensors have been developed for the perception of various stimuli. However, complex deformation,usually resulting from forces or strains from multi-axes, can be challenging to measure due to the lack of independent perception of multiaxial stimuli. Herein, flexible sensors based on the metamaterial membrane with zero Poisson's ratio(ZPR) are proposed to achieve independent detection of biaxial stimuli. By deliberately designing the geometric dimensions and arrangement parameters of elements, the Poisson's ratio of an elastomer membrane can be modulated from negative to positive, and the ZPR membrane can maintain a constant transverse dimension under longitudinal stimuli. Due to the accurate monitoring of grasping force by ZPR sensors that are insensitive to curvatures of contact surfaces, rigid robotic manipulators can be guided to safely grasp deformable objects. Meanwhile, the ZPR sensor can also precisely distinguish different states of manipulators. When ZPR sensors are attached to a thermal-actuation soft robot, they can accurately detect the moving distance and direction. This work presents a new strategy for independent biaxial stimuli perception through the design of mechanical metamaterials, and may inspire the future development of advanced flexible sensors for healthcare, human–machine interfaces and robotic tactile sensing.

关键词： zero Poisson's ratio metamaterials independent perception of multiaxial stimuli flexible sensor

Hybrid Strategy of Partitioned and Monolithic Methods for Solving Strongly Coupled Analysis of Inverse and Direct Piezoelectric and Circuit Coupling

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Computer Modeling in engineering & Sciences 2024年第8期140卷 1371-1386页

作者： Daisuke Ishihara Syunnosuke Nozaki Tomoya Niho Naoto Takayama department of intelligent and Control systems Kyushu Institute of TechnologyFukuokaJapan

The inverse and direct piezoelectric and circuit coupling are widely observed in advanced electro-mechanical systems such as piezoelectric energy *** strongly coupled analysis methods based on direct numerical modeling for this phenomenon can be classified into partitioned or monolithic *** formulation has its advantages and disadvantages,and the choice depends on the characteristics of each coupled *** study proposes a new option:a coupled analysis strategy that combines the best features of the existing formulations,namely,the hybrid partitioned-monolithic *** analysis of inverse piezoelectricity and the monolithic analysis of direct piezoelectric and circuit interaction are strongly coupled using a partitioned iterative hierarchical *** a typical benchmark problem of a piezoelectric energy harvester,this research compares the results from the proposed method to those from the conventional strongly coupled partitioned iterative method,discussing the accuracy,stability,and computational *** proposed hybrid concept is effective for coupled multi-physics problems,including various coupling conditions.

关键词： Structure-piezoelectric-circuit interaction energy harvesting partitioned method monolithic method hybrid method