DOCSLIB.ORG

Colloidal Electronics

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Colloidal Electronics by (Albert) Tianxiang Liu B.S. Chemical Engineering, California institute of Technology, 2014 SUBMITTED TO THE DEPARTMENT OF CHEMICAL ENGINEERING IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN CHEMICAL ENGINEERING AT THE MASSACHUSETTS INSTITUTE OF TECHNOLOGY July 2020 © 2020 Massachusetts Institute of Technology. All rights reserved. Signature of author ............................................................................................................................. Department of Chemical Engineering July 27, 2020 Certified by ........................................................................................................................................ Michael S. Strano Carbon P. Dubbs Professor of Chemical Engineering Thesis Supervisor Accepted by ....................................................................................................................................... Patrick S. Doyle Robert T. Haslam (1911) Professor of Chemical Engineering Graduate Officer 2 Colloidal Electronics by (Albert) Tianxiang Liu Submitted to the Department of Chemical Engineering on July 27, 2020, in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Chemical Engineering Abstract Arming nano-electronics with mobility extends artificial systems into traditionally inaccessible environments. Carbon nanotubes (1D), graphene (2D) and other low-dimensional materials with well-defined lattice structures can be incorporated into polymer microparticles, granting them unique electronic functions. The resulting colloidal electronic ‘cells’, comprised of microscopic circuits connecting artificial ‘organelles’ (e.g., generators, sensors, logic gates, etc.), combine the modularity of modern electronics with the characteristic mobility found in dispersive colloidal systems. Fundamental to colloidal electronics lie two challenges: (1) providing electrical energy to a microscopic system with limited footprint; and (2) developing energy efficient electronic devices and circuitries with low power consumption. In this context, my thesis introduces two concepts – Autoperforation and Asymmetric Chemical Doping – as means to fabricate and power electronic circuit elements on top of colloidal particles. These advances allow us to build the first colloidal electronic system that perform autonomous functions integrating energy harvesting, chemical detection and digital memory recording – all within a form-factor no larger than biological cells. Thesis Supervisor: Michael S. Strano, Carbon P. Dubbs Professor of Chemical Engineering 3 Acknowledgements I am forever grateful to have had Michael as my graduate advisor, who have continually fostered my scientific curiosity and encouraged my research independence. The extent to which his support has shaped my academic career cannot be overstated. Michael’s positivity, creativity, and scientific leadership have played a critical role in my growth as a scientist. I would like to thank Will Tisdale and Karthish Manthiram, for being a part of my Thesis Committee, for offering critical feedback at every step along the way, and for asking important questions to help me with my research and to steer me in the right direction. I would also like to thank Martin Bazant, Bill Deen, Jim Swan, Alan Hatton, and Klavs Jensen for their guidance and feedback on my thesis research. During my time at MIT, I have had many memorable moments as a teacher. I am grateful for the support of Bill Deen and Martin Bazant during my time as a TA for 10.50, of Klavs Jensen and Michael during my time as a TA for 10.65, of Michael during my time as a project consultant for 10.26, and Benjamin Hansberry for the Teaching Development Fellow program. I am extremely fortunate to have been surrounded by a group of talented colleagues within Michael’s group. I am particularly thankful to the help of Yuichiro Kunai, Anton Cottrill, Sayalee Mahajan, Pingwei Liu, Jingfan Yang, Ge Zhang, and Allan Brooks. I would also like to thank the students whom I have had a good fortune to work with: Stephen Gibbs, Jamila Smith- Dell, Max Saccone, Linh Nguyen, Rafid Mollah, Yannick Eatmon, Paul Baynard, Ian Timothy, and Lexy LeMar. 4 My thesis work has also greatly benefitted from a number of collaborators: Marek Hampel and Tomás Palacios from MIT, Ana Pervan and Todd Murphey from Northwestern, Paul McEuen from Cornell, Josh Daymude Andrea Richa from Arizona State, Dan Goldman and Dana Randall from Georgia Tech. I would also like to thank the following people who have helped me to navigate through career decisions: Michael, Karthish Manthiram, Connor Coley, Will Tisdale, Jim Swan, Bill Deen, Klavs Jensen, Kate Galloway, Ariel Furst, Crystal Chu, and Lennon Luo from MIT, Greg Fu, Mark Davis, John Seinfeld, Zhen-Gang Wang, and Max Saccone from Caltech, Ana Pervan and Todd Murphey from Northwestern, Josh Daymude from Arizona State, and Dana Randall from Georgia Tech. The past six years would not have been possible without my former scientific advisors: Jack Roberts, Greg Fu, Mark Davis, Stacey Zones, Steve Sieck, Jim Lindberg, Andy Mobley, and Heriberto Hernandez-Soto. These mentors have been, are, and will always be a source of inspiration. I can only hope to provide my own students with a small fraction of what they have provided me. I would not be where I am if it were not for my parents, Weimin Liu and Li Wang, and my partner, Stacey Fang. They have provided a tremendous amount of support in every way imaginable. For without their devotion, I would not have accomplished any of these, and without them, none of these accomplishments would have been meaningful. 5 Table of Contents Abstract ........................................................................................................................................... 3 Acknowledgements ......................................................................................................................... 4 Introduction to Colloidal Electronics .............................................................................................. 9 1.1 Colloidal State Machines: Autonomous Particles with On-Board Computation ........... 14 1.1.1 What are Colloidal State Machines? ....................................................................... 14 1.1.2 CSM Coagulation and Sedimentation ..................................................................... 17 1.1.3 Materials-Enabled CSM Modules........................................................................... 18 1.1.4 CSM Systems Integration ....................................................................................... 27 1.1.5 Control and Robotics of Autonomous CSMs ......................................................... 33 1.1.6 Application of CSMs .............................................................................................. 37 1.1.7 Conclusions and Outlook ........................................................................................ 40 1.2 Direct Electricity Generation Mediated by Molecular Interactions with Low Dimensional Carbon Materials – A Mechanistic Perspective .................................................. 42 1.2.1 Motivations for Solvent Mediated Energy Harvesting Methods ............................ 42 1.2.2 Mechanistic Overview ............................................................................................ 45 1.2.3 Perspectives, Application Space, and Energy Metrics .......................................... 112 1.3 References .................................................................................................................... 124 Sustainable Power Sources Based on High Efficiency Thermopower Wave Devices ............... 144 2.1 Background on Thermopower Wave Technology ....................................................... 145 2.2 High Efficiency Thermopower Wave Devices ............................................................ 146 2.3 References .................................................................................................................... 160 Electrical Energy Generation via Reversible Chemical Doping on Carbon Nanotube Fibers ... 163 3.1 Background on Excess Thermopower.......................................................................... 164 3.2 From Thermopower Wave to Asymmetric Chemical Doping ..................................... 166 3.3 Experimental Details .................................................................................................... 177 3.4 References .................................................................................................................... 179 Observation of the Marcus Inverted Region of Electron Transfer from Asymmetric Chemical Doping of Pristine (n, m) Single-Walled Carbon Nanotubes ..................................................... 182 4.1 Background on Asymmetric Chemical Doping ........................................................... 183 4.2 Asymmetric Chemical Doping Mechanism – an Electron Transfer Theory ................ 185 6 4.3 Experimental Details .................................................................................................... 203 4.4 References .................................................................................................................... 204 Solvent-Induced Electrocatalysis at an Asymmetric Carbon Interface ...................................... 207 5.1 Asymmetric Chemical Doping to Drive Electrochemical Transformations
Recommended publications

  • LIOC P R E S I D E N T , KEN HATFIELD and C H E E T a H CAESAR. C

    LIOC President, KEN HATFIELD and cheetah CAESAR. Caesar died recently at the age of 10 years of kidney and liver disease and is sorely missed as he was a great favorite of Ken's, often . ,. - - . h 1 vmT ic nn oaoe 13. Photo: George Collis Branch Representatives A.C.E.C. - Bob Smith, President, P.O. Box 26G, Los Angeles, CA 90026 (213) 621-4635 CANADA - Terry Foreman, Coordinator, R.R. #12, Dawson Rd., Thunder Bay, Ontario Canada P7B 5E3 CASCADE - Shelley Starns, 16635 Longmire Rd. S.E.. YeIm. WA 98597 (206) 894-2684 L.I.O.C. OF CALIFORNIA - Lora Vigne, 22 Isis St., San Francisco, CA 94102 (415) 552-3748 FLORIDA - Ken Hatfield (Acting President) 1991 S.W. 136 Ave., Davie, Florida 33325 (305) 472-7276 GREATER NEW YORK - Arthur Human, 32 Lockwood Ave., Norwalk, CT 06851 (203) 866-0484 PACIFIC NORTHWEST - Gayle Schaecher, 10715 S.E. Orient Dr., Boring, OR 97009 (503) 633-4673 SOUTHWESTERN - Rebecca Morgan, President, P.O. Box 144, Carrollton, TX 75006 (214) 241-6440 LONG ISLAND OCELOT CLUB EXOTIC CATSIGEORGIA - Cat Klass, President, 4704 NEWSLETTER Brownsville Rd., Powder Springs, GA 30073 (404) 943- 2809 Published bi-monthly by Long Island Ocelot Club. 1454 Fleetwood OREGON EDUCATIONAL EXOTIC FELINE CLUB - Drive East, Mobile. Alabama 36605. The Long Island Ocelot Club is a Barbara Wilton, 7800 S.E. Luther Rd., Portland, OR non-profit, non-commercial club. international in membership, 97206 (503) 774-1657 , devoted to the welfare of ocelots and all other exotic felines. Reproduction of the material in this Newsletter may not be made without written permission of the authors and/or the copyright owner L.I.O.C.
  • Shape-Memory Polymeric Artificial Muscles Stress That Is Applied to the Polymer [8,70]

    Shape-Memory Polymeric Artificial Muscles Stress That Is Applied to the Polymer [8,70]

    molecules Review Shape-Memory Polymeric Artificial Muscles: Mechanisms, Applications and Challenges 1, 1, 1, , 1 2 2 Yujie Chen y , Chi Chen y, Hafeez Ur Rehman * y, Xu Zheng , Hua Li , Hezhou Liu and Mikael S. Hedenqvist 3,* 1 State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China; [email protected] (Y.C.); [email protected] (C.C.); [email protected] (X.Z.) 2 Collaborative Innovation Centre for Advanced Ship and Dee-Sea Exploration, Shanghai Jiao Tong University, Shanghai 200240, China; [email protected] (H.L.); [email protected] (H.L.) 3 Department of Fibre and Polymer Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden * Correspondence: [email protected] (H.U.R.); [email protected] (M.S.H.) These authors contributed equally to this work. y Academic Editor: Laura Peponi Received: 7 July 2020; Accepted: 3 September 2020; Published: 16 September 2020 Abstract: Shape-memory materials are smart materials that can remember an original shape and return to their unique state from a deformed secondary shape in the presence of an appropriate stimulus. This property allows these materials to be used as shape-memory artificial muscles, which form a subclass of artificial muscles. The shape-memory artificial muscles are fabricated from shape-memory polymers (SMPs) by twist insertion, shape fixation via Tm or Tg, or by liquid crystal elastomers (LCEs). The prepared SMP artificial muscles can be used in a wide range of applications, from biomimetic and soft robotics to actuators, because they can be operated without sophisticated linkage design and can achieve complex final shapes.
  • Electronic Structure of Graphene– and BN–Supported Phosphorene

    Electronic Structure of Graphene– and BN–Supported Phosphorene

    This document is downloaded from DR‑NTU (https://dr.ntu.edu.sg) Nanyang Technological University, Singapore. Electronic structure of graphene– and BN–supported phosphorene Kistanov, Andrey A.; Saadatmand, Danial; Dmitriev, Sergey V.; Zhou, Kun; Korznikova, Elena A.; Davletshin, Artur R.; Ustiuzhanina, Svetlana V. 2018 Davletshin, A. R., Ustiuzhanina, S. V., Kistanov, A. A., Saadatmand, D., Dmitriev, S. V., Zhou, K., & Korznikova, E. A. (2018). Electronic structure of graphene– and BN–supported phosphorene. Physica B: Condensed Matter, 534, 63‑67. doi:10.1016/j.physb.2018.01.039 https://hdl.handle.net/10356/90092 https://doi.org/10.1016/j.physb.2018.01.039 © 2018 Elsevier B.V. All rights reserved. This paper was published in Physica B: Condensed Matter and is made available with permission of Elsevier B.V. Downloaded on 02 Oct 2021 11:03:45 SGT Electronic structure of graphene– and BN–supported phosphorene Artur R. Davletshin1, Svetlana V. Ustiuzhanina2, *Andrey A. Kistanov2, 3 , 4, Danial Saadatmand5, Sergey V. Dmitriev2, 6, Kun Zhou3 and Elena A. Korznikova2 1Ufa State Petroleum Technological University, Ufa 450000, Russia 2Institute for Metals Superplasticity Problems, Russian Academy of Sciences, Ufa 450001, Russia 3School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798, Singapore 4Institute of High Performance Computing, Agency for Science, Technology and Research, Singapore 138632, Singapore 5Department of Physics, University of Sistan and Baluchestan, Zahedan, Iran 6National Research Tomsk State University, Tomsk 634050, Russia Abstract By using first–principles calculations, the effects of graphene and boron nitride (BN) substrates on the electronic properties of phosphorene are studied. Graphene–supported phosphorene is found to be metallic, while the BN–supported phosphorene is a semiconductor with a moderate band gap of 1.02 eV.
  • Technology and Applications of 2D Materials in Micro- and Macroscale Electronics

    Technology and Applications of 2D Materials in Micro- and Macroscale Electronics

    Technology and Applications of 2D Materials in Micro- and Macroscale Electronics by Marek Hempel B.S., RWTH Aachen University (2010) M.S., RWTH Aachen University (2013) Submitted to the Department of Electrical Engineering and Computer Science in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY May 2020 © Massachusetts Institute of Technology 2020. All rights reserved. Author ……………………………………………………………………………………………………………………………………………………… Department of Electrical Engineering and Computer Science May 15, 2020 Certified by ………………………………………………………………………………………………………………………………………………. Tomás Palacios Professor of Electrical Engineering and Computer Science Thesis Supervisor Certified by ………………………………………………………………………………………………………………………………………………. Jing Kong Professor of Electrical Engineering and Computer Science Thesis Supervisor Accepted by ……………………………………………………………………………………………………………………………………………… Leslie A. Kolodziejski Professor of Electrical Engineering and Computer Science Chair, Department Committee on Graduate Students 1 2 Technology and Applications of 2D-Materials in Micro- and Macroscale Electronics by Marek Hempel Submitted to the Department of Electrical Engineering and Computer Science on May 15, 2020, in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Abstract: Over the past 50 years, electronics has truly revolutionized our lives. Today, many everyday objects rely on electronic circuitry from gadgets such as wireless earbuds, smartphones and
  • Arxiv:1407.5880V3 [Cond-Mat.Mes-Hall] 14 Aug 2014

    Arxiv:1407.5880V3 [Cond-Mat.Mes-Hall] 14 Aug 2014

    Oxygen defects in phosphorene A. Ziletti,1 A. Carvalho,2 D. K. Campbell,3 D. F. Coker,1, 4 and A. H. Castro Neto2, 3 1Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston Massachusetts 02215, USA 2Graphene Research Centre and Department of Physics, National University of Singapore, 117542, Singapore 3Department of Physics, Boston University, 590 Commonwealth Avenue, Boston Massachusetts 02215, USA 4Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, D-79104, Freiburg, Germany Surface reactions with oxygen are a fundamental cause of the degradation of phosphorene. Using first-principles calculations, we show that for each oxygen atom adsorbed onto phosphorene there is an energy release of about 2 eV. Although the most stable oxygen adsorbed forms are electrically inactive and lead only to minor distortions of the lattice, there are low energy metastable forms which introduce deep donor and/or acceptor levels in the gap. We also propose a mechanism for phosphorene oxidation and we suggest that dangling oxygen atoms increase the hydrophilicity of phosphorene. PACS numbers: 73.20.At,73.20.Hb Phosphorene, a single layer of black phosphorus[1, 2], phosphorene is exoenergetic and leads to the formation of has revealed extraordinary functional properties which neutral defects, as well as to metastable electrically active make it a promising material not only for exploring novel defect forms. We also discuss the conditions necessary for physical phenomena but also for practical applications. extensive oxidation and propose strategies to control it. In contrast to graphene, which is a semi-metal, phospho- Oxygen defects were modeled using first-principles cal- rene is a semiconductor with a quasiparticle band gap of 2 culations based on density functional theory (DFT), as eV.
  • Reconfigurable Polarizer Based on Bulk Dirac Semimetal Metasurface

    Reconfigurable Polarizer Based on Bulk Dirac Semimetal Metasurface

    crystals Article Reconfigurable Polarizer Based on Bulk Dirac Semimetal Metasurface Yannan Jiang, Jing Zhao and Jiao Wang * Guangxi Key Laboratory of Wireless Wideband Communication & Signal Processing, Guilin 541000, China; [email protected] (Y.J.); [email protected] (J.Z.) * Correspondence: [email protected] Received: 22 February 2020; Accepted: 16 March 2020; Published: 21 March 2020 Abstract: In this paper, we propose a reflective polarizer in terahertz regime, which utilizes the Bulk-Dirac-Semimetal (BDS) metasurface can be dynamically tuned in broadband. The proposed polarizer is capable of converting the linear polarized wave into the circular polarized or the cross polarized waves by adjusting the Fermi energy (EF) of the BDS. In the frequency range of 0.51 THz and 1.06 THz, the incident linear polarized wave is converted into a circular polarized wave with an axial ratio (AR) less than 3 dB when EF = 30 meV. When EF = 45 meV, the cross-polarization conversion is achieved with the polarization conversion ratio (PCR) greater than 90% in the band of 0.57 1.12 THz. Meanwhile, the conversion efficiencies for both polarization conversions are in − excess of 90%. Finally, the physical mechanism is revealed by the decomposition of two orthogonal components and the verification is presented by the interference theory. Keywords: reconfigurable polarizer; tunable metasurface; broadband; Bulk-Dirac-Semimetal 1. Introduction In recent years, terahertz (THz) technology has developed rapidly in many fields, such as sensing [1], imaging [2] and radar [3] because terahertz waves have very low photon energy, strong penetrability, and obvious characteristic absorption peaks, making terahertz technology show significant research value and great prospects in material detection, security inspection, military, and wireless communications.
  • An Unexplored 2D Semiconductor with a High Hole Mobility Han Liu Purdue University, Birck Nanotechnology Center, Hanliu@Purdue.Edu

    An Unexplored 2D Semiconductor with a High Hole Mobility Han Liu Purdue University, Birck Nanotechnology Center, [email protected]

    Purdue University Purdue e-Pubs Birck and NCN Publications Birck Nanotechnology Center 4-2014 Phosphorene: An Unexplored 2D Semiconductor with a High Hole Mobility Han Liu Purdue University, Birck Nanotechnology Center, [email protected] Adam T. Neal Purdue University, Birck Nanotechnology Center, [email protected] Zhen Zhu Michigan State University Xianfan Xu Purdue University, Birck Nanotechnology Center, [email protected] David Tomanek Michigan State University See next page for additional authors Follow this and additional works at: http://docs.lib.purdue.edu/nanopub Part of the Nanoscience and Nanotechnology Commons Liu, Han; Neal, Adam T.; Zhu, Zhen; Xu, Xianfan; Tomanek, David; Ye, Peide D.; and Luo, Zhe, "Phosphorene: An Unexplored 2D Semiconductor with a High Hole Mobility" (2014). Birck and NCN Publications. Paper 1584. http://dx.doi.org/10.1021/nn501226z This document has been made available through Purdue e-Pubs, a service of the Purdue University Libraries. Please contact [email protected] for additional information. Authors Han Liu, Adam T. Neal, Zhen Zhu, Xianfan Xu, David Tomanek, Peide D. Ye, and Zhe Luo This article is available at Purdue e-Pubs: http://docs.lib.purdue.edu/nanopub/1584 ARTICLE Phosphorene: An Unexplored 2D Semiconductor with a High Hole Mobility Han Liu,†,‡ Adam T. Neal,†,‡ Zhen Zhu,§ Zhe Luo,‡,^ Xianfan Xu,‡,^ David Toma´ nek,§ and Peide D. Ye†,‡,* †School of Electrical and Computer Engineering and ‡Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States, §Physics and Astronomy Department, Michigan State University, East Lansing, Michigan 48824, United States, and ^School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907, United States ABSTRACT We introduce the 2D counterpart of layered black phosphorus, which we call phosphorene, as an unexplored p-type semiconducting material.
  • 3D Printable Linear Soft Vacuum Actuators: Their Modeling, Performance Quantification and Application in Soft Robotic Systems

    3D Printable Linear Soft Vacuum Actuators: Their Modeling, Performance Quantification and Application in Soft Robotic Systems

    University of Wollongong Research Online Faculty of Engineering and Information Faculty of Engineering and Information Sciences - Papers: Part B Sciences 2019 3D Printable Linear Soft Vacuum Actuators: Their Modeling, Performance Quantification and Application in Soft Robotic Systems Charbel Tawk University of Wollongong, [email protected] Geoffrey M. Spinks University of Wollongong, [email protected] Marc in het Panhuis University of Wollongong, [email protected] Gursel Alici University of Wollongong, [email protected] Follow this and additional works at: https://ro.uow.edu.au/eispapers1 Part of the Engineering Commons, and the Science and Technology Studies Commons Recommended Citation Tawk, Charbel; Spinks, Geoffrey M.; in het Panhuis, Marc; and Alici, Gursel, "3D Printable Linear Soft Vacuum Actuators: Their Modeling, Performance Quantification and Application in Soft Robotic Systems" (2019). Faculty of Engineering and Information Sciences - Papers: Part B. 3375. https://ro.uow.edu.au/eispapers1/3375 Research Online is the open access institutional repository for the University of Wollongong. For further information contact the UOW Library: [email protected] 3D Printable Linear Soft Vacuum Actuators: Their Modeling, Performance Quantification and Application in Soft Robotic Systems Abstract Conventional robotic systems have proved their versatility in the industry where complex tasks requiring high force, high speed and high precision are desired. However, these rigid-bodied systems cannot collaborate safely with humans.
  • Two-Dimensional Mos2 Electromechanical Actuators

    Two-Dimensional Mos2 Electromechanical Actuators

    Two-dimensional MoS2 electromechanical actuators Nguyen T. Hung1, Ahmad R. T. Nugraha1, Riichiro Saito1 1Department of Physics, Tohoku University, Sendai 980-8578, Japan E-mail: [email protected] February 2014 Abstract. We investigate electromechanical properties of two-dimensional MoS2 monolayers in the 1H, 1T, and 1T0 structures as a function of charge doping by using density functional theory. We find isotropic elastic moduli in the 1H and 1T structures, while the 1T0 structure exhibits an anisotropic elastic modulus. Moreover, the 1T structure is shown to have a negative Poisson's ratio, while Poisson's ratios of the 0 1H and 1T are positive. By charge doping, the monolayer MoS2 shows a reversibly strain and work density per cycle ranging from −0:68% to 2:67% and from 4.4 to 36.9 MJ/m3, respectively, making them suitable for applications in electromechanical actuators. Stress generated is also examined in this work and we find that 1T and 1T0 MoS2 monolayers relatively have better performance than 1H MoS2 monolayer. We argue that such excellent electromechanical performance originate from the electrical conductivity of the metallic 1T and semimetallic 1T0 structures high Young's modulus of about 150 − 200 GPa. arXiv:1711.00188v1 [cond-mat.mtrl-sci] 1 Nov 2017 Two-dimensional MoS2 electromechanical actuators 2 1. Introduction Natural muscle is an example of good-performance actuator with work cycles involving contractions of more than 20%, although the stress generation ability of natural muscle is quite low (0:35 MPa) [1] compared with mechanical machine. Various actuation materials have been studied to replace natural muscle that can directly convert electrical energy into mechanical energy, with wide potential applications in soft robotics, adaptive wings for aircraft, and biometric machines [1].
  • Science & Technology Trends 2020-2040

    Science & Technology Trends 2020-2040

    Science & Technology Trends 2020-2040 Exploring the S&T Edge NATO Science & Technology Organization DISCLAIMER The research and analysis underlying this report and its conclusions were conducted by the NATO S&T Organization (STO) drawing upon the support of the Alliance’s defence S&T community, NATO Allied Command Transformation (ACT) and the NATO Communications and Information Agency (NCIA). This report does not represent the official opinion or position of NATO or individual governments, but provides considered advice to NATO and Nations’ leadership on significant S&T issues. D.F. Reding J. Eaton NATO Science & Technology Organization Office of the Chief Scientist NATO Headquarters B-1110 Brussels Belgium http:\www.sto.nato.int Distributed free of charge for informational purposes; hard copies may be obtained on request, subject to availability from the NATO Office of the Chief Scientist. The sale and reproduction of this report for commercial purposes is prohibited. Extracts may be used for bona fide educational and informational purposes subject to attribution to the NATO S&T Organization. Unless otherwise credited all non-original graphics are used under Creative Commons licensing (for original sources see https://commons.wikimedia.org and https://www.pxfuel.com/). All icon-based graphics are derived from Microsoft® Office and are used royalty-free. Copyright © NATO Science & Technology Organization, 2020 First published, March 2020 Foreword As the world Science & Tech- changes, so does nology Trends: our Alliance. 2020-2040 pro- NATO adapts. vides an assess- We continue to ment of the im- work together as pact of S&T ad- a community of vances over the like-minded na- next 20 years tions, seeking to on the Alliance.
  • Modulation of Phosphorene for Optimal Hydrogen Evolution Reaction

    Modulation of Phosphorene for Optimal Hydrogen Evolution Reaction

    Research Article Cite This: ACS Appl. Mater. Interfaces 2019, 11, 37787−37795 www.acsami.org Modulation of Phosphorene for Optimal Hydrogen Evolution Reaction † † † † † ‡ † § Jiang Lu, Xue Zhang, Danni Liu, Na Yang, Hao Huang, Shaowei Jin, Jiahong Wang,*, , § † Paul K. Chu, and Xue-Feng Yu † Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, P. R. China ‡ National Supercomputing Center, Shenzhen, Guangdong 518055, P. R. China § Department of Physics, Department of Materials Science and Engineering, and Department of Biomedical Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China *S Supporting Information ABSTRACT: Economical and highly effective catalysts are crucial to the electrocatalytic hydrogen evolution reaction (HER), and few-layer black phosphorus (phosphorene) is a promising candidate because of the high carrier mobility, large specific surface area, and tunable physicochemical characteristics. However, the HER activity of phosphorene is limited by the weak hydrogen adsorption ability on the basal plane. In this work, optimal active sites are created to modulate the electronic structure of phosphorene to improve the HER activity and the effectiveness is investigated theoretically by density-functional theory calculation and verified experimentally. The edges and defects affect the electronic density of states, and a linear relationship between the HER activity and lowest unoccupied states ε ε ( LUS) is discovered. The medium LUS value corresponds to the suitable hydrogen adsorption strength. Experiments are designed and performed to verify the prediction, and our results show that a smaller phosphorene moiety with more edges and defects exhibits better HER activity and surface doping with metal adatoms improves the catalytic performance.
  • Direct Writing Corrugated PVC Gel Artificial Muscle Via Multi-Material

    Direct Writing Corrugated PVC Gel Artificial Muscle Via Multi-Material

    polymers Article Direct Writing Corrugated PVC Gel Artificial Muscle via Multi-Material Printing Processes Bin Luo 1,2,3,*, Yiding Zhong 2, Hualing Chen 1,2,*, Zicai Zhu 2 and Yanjie Wang 4 1 State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an 710049, China 2 School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049, China; [email protected] (Y.Z.); [email protected] (Z.Z.) 3 School of Mechanical and Energy Engineering, Shaoyang University, Shaoyang 422000, China 4 Changzhou Campus, School of Mechanical and Electrical Engineering, Hohai University, Changzhou 213022, China; [email protected] * Correspondence: [email protected] (B.L.); [email protected] (H.C.) Abstract: Electroactive PVC gel is a new artificial muscle material with good performance that can mimic the movement of biological muscle in an electric field. However, traditional manufacturing methods, such as casting, prevent the broad application of this promising material because they cannot achieve the integration of the PVC gel electrode and core layer, and at the same time, it is difficult to create complex and diverse structures. In this study, a multi-material, integrated direct writing method is proposed to fabricate corrugated PVC gel artificial muscle. Inks with suitable rheological properties were developed for printing four functional layers, including core layers, electrode layers, sacrificial layers, and insulating layers, with different characteristics. The curing conditions of the printed CNT/SMP inks under different applied conditions were also discussed. The structural parameters were optimized to improve the actuating performance of the PVC gel artificial Citation: Luo, B.; Zhong, Y.; Chen, muscle.