The origin of contact-electrification - how can the 2600 years old physics phenomenon contribute to the world energy in the future?
接触起电的机理 - 揭秘一个2600年老的科学问题如何对世界未来的能源有重大贡献？
Zhong Lin Wang（王中林）
ABSRACT
Contact electrification (CE) (or usually called “triboelectrification”) effect, the most fundamental effect for electricity, has been known for over 2600 years since ancient Greek time, but its scientific mechanism remains unclear. The study of triboelectrification is recently revived due to the invention of the triboelectric nanogenerators (TENGs) by using the coupling of triboelectrification and electrostatic induction effects, which is the most effective approach for converting mechanical energy into electricity for powering small sensors. TENG is playing a vitally important role in the distributed energy and self-powered systems, with applications in internet of things, environmental/infrastructural monitoring, medical science, environmental science and security. In this talk, we first present the physics mechanism of triboelectrification for general materials. Our model is extended to liquid-solid contact electrification, reviving the classical understanding about the formation of electric double layers. Secondly, the fundamental theory of the TENGs is explored based on a group of reformulated Maxwell equations. In the Maxwell’s displacement current proposed in 1861, the term e¶E/¶t gives the birth of electromagnetic wave, which is the foundation of wireless communication, radar and later the information technology. Our study indicates that, owing to the presence of surface polarization charges present on the surfaces of the dielectric media in TENG, an additional term ¶Ps/¶t that is due to non-electric field induced polarization should be added in the Maxwell’s displacement current, which is the output electric current of the TENG. Therefore, our TENGs are the applications of Maxwell’s displacement current in energy and sensors. We will present the applications of the TENGs for harvesting all kind mechanical energy that is available but wasted in our daily life, such as human motion, walking, vibration, mechanical triggering, rotating tire, wind, flowing water and more. Then, we will illustrate the networks based on triboelectric TENGs for harvesting ocean water wave energy, for exploring its possibility as a sustainable large-scale blue energy. Lastly, we will show that TENGs as self-powered sensors for actively detecting the static and dynamic processes arising from mechanical agitation using the voltage and current output signals.
接触起电，又被称为摩擦电效应，是自然界中最基本的电学效应，从2600年前的古希腊时期就为人们所熟知，但它的科学机理尚不明确。近年来，基于摩擦起电与静电感应效应的摩擦纳米发电机被科研人员提出，极大的促进了摩擦电领域的研究，是将机械能转换为电能并进一步驱动小型传感器件的最为有效的方式。摩擦纳米发电机在分布式能源与自供能系统等领域扮演了越来越重要的角色，并在物联网、环境监测、医疗科学等方面展现了突出的应用前景。本次研究，我们将首先介绍一般材料的摩擦起电物理机理，进一步延伸到固液界面接触起电以进一步了解双电层的形成过程。其次，基于麦克斯韦方程组，探讨摩擦纳米发电机的基本理论框架，证实了其是麦克斯韦方程组在能源与传感器领域的应用拓展。接下来，展现摩擦纳米发电机在收集生活中各类机械能的潜力，包括人体运动、行走、振动、风以及水流等等，并基于网络化摩擦纳米发电机收集海洋波动能量，探索其作为可持续大规模蓝色能源的可行性。最后，我们会展示摩擦纳米发电机作为自供能传感器，利用电压和电流作为输出信号，实现静态与动态力学信号的主动式传感的功能。
BIOGRAPHY
Dr. Zhong Lin Wang is the Hightower Chair in Materials Science and Engineering and Regents' Professor at Georgia Tech，and Founding Director of the Beijing Institute of Nanoenergy and Nanosystems. Dr. Wang pioneered the nanogenerators from fundamental science to technological applications. His research on self-powered nanosystems has inspired the worldwide effort in academia and industry for studying energy for micro-nano-systems. He coined and pioneered the fields of piezotronics and piezo-phototronics for the third generation semiconductors. Wang is ranked #15 among 100,000 scientists across all fields worldwide. His google scholar citation is over 230,000 with an h-index of over 238.
Dr. Wang has received the Celsius Lecture Laureate, Uppsala University, Sweden (2020); The Albert Einstein World Award of Science (2019); Diels-Planck lecture award (2019); ENI award in Energy Frontiers (2018); Global Nanoenergy Prize, The NANOSMAT Society, UK (2017); Distinguished Research Award, Pan Wen Yuan foundation (2017); Distinguished Scientist Award from (US) Southeastern Universities Research Association (2016); Thomas Router Citation Laureate in Physics (2015); World Technology Award (Materials) (2014); Distinguished Professor Award (Highest faculty honor at Georgia Tech) (2014); NANOSMAT prize (United Kingdom) (2014); The James C. McGroddy Prize in New Materials from American Physical Society (2014); MRS Medal from Materials Research Soci. (2011).
Dr. Wang was elected as a foreign member of the Chinese Academy of Sciences in 2009, member of European Academy of Sciences in 2002, academician of Academia of Sinica 2018, International fellow of Canadian Academy of Engineering 2019; Foreign member of the Korean Academy of Science and Technology 2019; fellow of American Physical Society in 2005, fellow of AAAS in 2006, fellow of Materials Research Society in 2008, fellow of Microscopy Society of America in 2010, fellow of the World Innovation Foundation in 2002, fellow of Royal Society of Chemistry, and fellow of World Technology Network 2014. Dr. Wang is the founding editor and chief editor of an international journal Nano Energy, which now has an impact factor of 15.5. Details can be found at: http://www.nanoscience.gatech.edu
王中林教授，中国科学院北京纳米能源与系统所所长，佐治亚理工学院终身校董、Hightower终身讲席教授。王中林教授是纳米能源研究领域的奠基人，发明了压电纳米发电机与摩擦纳米发电机，并首次提出自驱动系统与蓝色能源的大概念，将纳米能源定义为“新时代的能源”。王中林教授开创了压电电子学与压电光电子学两大学科，提出的原创新物理效应引领了第三代半导体纳米材料的基础研究。王中林教授Google Scholar统计的学术论文引用超过23万次，个人h-index为238，在世界范围内横跨所有领域的10万名科学家综合排名中名列第15名。
王中林教授先后当选中国科学院外籍院士、欧洲科学院院士、加拿大工程院外籍院士，已被选为以下美国物理协会(APS)、美国科学促进会(AAAS)、美国材料研究协会(MRS)、美国显微协会(MSA)、英国皇家化学学会(RSC)等国际专业学会的会士(Fellow)。王中林教授曾获评摄氏-林耐讲座奖(2020年)、爱因斯坦世界科学奖(2019年)、埃尼奖(2018年)、全球纳米能源奖(2017年)、汤森路透引文桂冠奖(2015年)等多项重量级奖项。他是国际纳米能源领域著名期刊《Nano Energy》的创刊者与现任主编，该期刊最新影响因子为15.548。