scholarly journals Programmable self-propelling actuators enabled by a dynamic helical medium

2021 ◽  
Vol 7 (32) ◽  
pp. eabh3505
Author(s):  
Ling-Ling Ma ◽  
Chao Liu ◽  
Sai-Bo Wu ◽  
Peng Chen ◽  
Quan-Ming Chen ◽  
...  
Keyword(s):  
Photon Energy ◽  
Power Transmission ◽  
Functional Materials ◽  
Molecular Assembly ◽  
Unique Case ◽  
Self Organized ◽  
Orbital Revolution ◽  
Intelligent Robotics

Rotation-translation conversion is a popular way to achieve power transmission in machinery, but it is rarely selected by nature. One unique case is that of bacteria swimming, which is based on the collective reorganization and rotation of flagella. Here, we mimic such motion using the light-driven evolution of a self-organized periodic arch pattern. The range and direction of translation are altered by separately varying the alignment period and the stimulating photon energy. Programmable self-propelling actuators are realized via a specific molecular assembly within a photoresponsive cholesteric medium. Through rationally presetting alignments, parallel transports of microspheres in customized trajectories are demonstrated, including convergence, divergence, gathering, and orbital revolution. This work extends the understanding of the rotation-translation conversion performed in an exquisitely self-organized system and may inspire future designs for functional materials and intelligent robotics.

A Fuzzy-Based Congestion Control Scheme for Vehicular Adhoc Network Communication

2021 ◽  
Vol 4 (1) ◽  
pp. 1-15
Author(s):  
Samuel Ibukun Olotu ◽  
Olumide Sunday Adewale ◽  
Bolanle Adefowoke Ojokoh
Keyword(s):  
Congestion Control ◽  
Ad Hoc ◽  
Power Transmission ◽  
Transmission Rate ◽  
Contention Window ◽  
Delivery Ratio ◽  
Self Organized ◽  
Traffic Scenario ◽  
Service Oriented ◽  
Parameter Values

Vehicular ad hoc network (VANET) is a self-organized, multi-purpose, service-oriented communication network that enables communication between vehicles and between vehicles and roadside infrastructures for the purpose of exchanging messages. In a dense traffic scenario, the message traffic may generate a load higher than the available capacity of the transmission medium leading to channel congestion problem. This situation leads to a rise in packet loss rates and transmission delay. Some existing congestion control schemes adapt the transmission power, transmission rate, and contention window parameters by making comparison with neighboring values through classical logic. However, the approach does not consider points between two close parameter values. This work uses fuzzy logic to improve the adaptation process of the network contention window parameter. The proposed scheme achieved a 15% higher in-packet delivery ratio and 10ms faster transmission compared with related work in terms end-to-end delay.

UHV-TEM/REM Study of Palladium Silicide Islands Grown on Silicon (111) 7×7 Surface

2001 ◽  
Vol 7 (S2) ◽  
pp. 318-319
Author(s):  
M. Takeguchi ◽  
K. Mitsuishi ◽  
J. Liu ◽  
Q. Zhang ◽  
M. Tanaka ◽  
...  
Keyword(s):  
Electron Beam ◽  
Functional Materials ◽  
Side Surface ◽  
Beam Direction ◽  
Self Organized ◽  
Reflection Electron Microscopy ◽  
Rectangular Specimen ◽  
Palladium Silicide ◽  
Transmission And Reflection

The growth of self-organized nanoislands and nanowires on a substrate has been extensively studied with a view to fabricating the new functional materials and advanced electric devices. in the present work, Pd silicide islands and wires grown on Si (111) 7x77×7surface were observed in situ by ultrahigh vacuum transmission and reflection electron microscopy (UHV-TEM/REM). Pd was deposited on Si (111) 7×7 surface at about 700 K using an electron beam evaporator attached to the column of a UHV microscope. Two kinds of specimens were prepared: a <111> oriented rectangular specimen with a thin area, whose (111) top surface was observed by plan viewed TEM, and a <110> oriented bulk rectangular specimen, whose (111) side surface was observed by REMFigure la shows a REM image of Si (111) 7×7 surface. An incident electron beam is directed from the top to the bottom of the figure, which is foreshortened in the beam direction.

Soft material nanoarchitectonics at interfaces: molecular assembly, nanomaterial synthesis, and life control

2019 ◽  
Vol 4 (1) ◽  
pp. 49-64 ◽  
Author(s):  
Katsuhiko Ariga ◽  
Xiaofang Jia ◽  
Lok Kumar Shrestha
Keyword(s):  
Functional Materials ◽  
Molecular Assembly ◽  
Soft Material ◽  
Nanomaterial Synthesis

Nanoarchitectonics would be a breakthrough paradigm for preparation of functional materials with soft material components from nanoscale units.

Highly fluorescent free-standing films assembled from perylenediimide microcrystals for boosting aniline sensing

2020 ◽  
Vol 8 (4) ◽  
pp. 1421-1426 ◽  
Author(s):  
Baozhong Lü ◽  
Pengyu Li ◽  
Pengfei Li ◽  
Yantu Zhang ◽  
Klaus Müllen ◽  
...  
Keyword(s):  
Functional Materials ◽  
Molecular Assembly ◽  
Free Standing

Molecular assembly has emerged as a key protocol for designing functional materials, although building in task-specific applications remains challenging.

scholarly journals Emerging functional materials based on chemically designed molecular recognition

BMC Materials ◽  
2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Wei Chen ◽  
Xiaohua Tian ◽  
Wenbo He ◽  
Jianwei Li ◽  
Yonghai Feng ◽  
...  
Keyword(s):  
Molecular Recognition ◽  
Material Science ◽  
Rational Design ◽  
Dynamic Properties ◽  
Functional Materials ◽  
Molecular Assembly ◽  
Modern Material ◽  
Chemical Recognition ◽  
Fundamental Research ◽  
Modern Material Science

AbstractThe specific interactions responsible for molecular recognition play a crucial role in the fundamental functions of biological systems. Mimicking these interactions remains one of the overriding challenges for advances in both fundamental research in biochemistry and applications in material science. However, current molecular recognition systems based on host–guest supramolecular chemistry rely on familiar platforms (e.g., cyclodextrins, crown ethers, cucurbiturils, calixarenes, etc.) for orienting functionality. These platforms limit the opportunity for diversification of function, especially considering the vast demands in modern material science. Rational design of novel receptor-like systems for both biological and chemical recognition is important for the development of diverse functional materials. In this review, we focus on recent progress in chemically designed molecular recognition and their applications in material science. After a brief introduction to representative strategies, we describe selected advances in these emerging fields. The developed functional materials with dynamic properties including molecular assembly, enzyme-like and bio-recognition abilities are highlighted. We have also selected materials with dynamic properties in contract to traditional supramolecular host–guest systems. Finally, the current limitations and some future trends of these systems are discussed.

NANOFABRICATION BY COVALENT MOLECULAR ASSEMBLY: A PATHWAY TO ROBUST STRUCTURES

COSMOS ◽  
2011 ◽  
Vol 07 (01) ◽  
pp. 31-42
Author(s):  
S. PUNIREDDY ◽  
S. JAYARAMAN ◽  
R. K. GUPTA ◽  
S. H. YEONG ◽  
F. ZHANG ◽  
...  
Keyword(s):  
Molecular Orientation ◽  
Mechanical Stability ◽  
Functional Materials ◽  
Molecular Assembly ◽  
Layer By Layer ◽  
Residual Solvent ◽  
Lbl Assembly ◽  
Wide Range ◽  
Free Environment ◽  
Areas Of Interest

A wide range of new materials for many applications can be formed by controlling the composition and order of constituents at the molecular level. For systems thus engineered, ensuring chemical, thermal and mechanical robustness is a major challenge. Consequently, polyimides and other imide-containing materials are attractive as matrices for functional materials. We investigate the construction of functional nanostructures in organic/polymeric matrices with clearly demonstrated chemical, thermal and mechanical stability. Surface functionalization, layer-by-layer (LBL) assembly in various media (including supercritical), incorporation of functional moieties, molecular orientation, and interfacial reactions are areas of interest. We demonstrate the robustness of ultrathin film structures containing polyimides and oligoimides formed by LBL molecular assembly with inter-layer covalent links. Covalent bonding between the layers provides strength, while utilizing a supercritical medium for the processing, results in the deployment of a solvent-free environment and avoids problems related to residual solvent, thereby improving film quality when compared to conventional films.

Multiple Fault Identification Using Vibration Signal Analysis and Artificial Intelligence Methods

2013 ◽  
Vol 430 ◽  
pp. 63-69 ◽  
Author(s):  
Ninoslav Zuber ◽  
Dragan Cvetkovic ◽  
Rusmir Bajrić
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Power Transmission ◽  
Vibration Signal ◽  
Single Type ◽  
Feature Maps ◽  
Multiple Faults ◽  
Self Organized ◽  
Artificial Neural ◽  
Vibration Signal Analysis

Paper addresses the implementation of feature based artificial neural networks and self-organized feature maps with the vibration analysis for the purpose of automated faults identification in rotating machinery. Unlike most of the research in this field, where a single type of fault has been treated, the research conducted in this paper deals with rotating machines with multiple faults. Combination of different roller elements bearing faults and different gearbox faults is analyzed. Experimental work has been conducted on a specially designed test rig. Frequency and time domain vibration features are used as inputs to fault classifiers. A complete set of proposed vibration features are used as inputs for self-organized feature maps and based on the results they are used as inputs for supervised artificial neural networks. The achieved results show that proposed set of vibration features enables reliable identification of developing bearing and gear faults in geared power transmission systems.

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