报告题目：The physics of contact-electrification and the theory of triboelectric nanogenerators
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. 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.
 Z.L. Wang and A.C. Wang. On the origin of contact electrification, Materials Today, 30 (2019) 34-51.
 S. Lin, L. Xu, A.C. Wang and Z.L. Wang. Quantifying electron-transfer and ion-transfer in liquid-solid contact electrification and the formation mechanism of electric double-layer, Nature Communication, 11 (2020) 399.
 Z.L. Wang, On the first principle theory of nanaogenerators from Maxwell’s equations, Nano Energy, 68 (2020) 104272.
Dr. Zhong Lin Wang is the Director of the Beijing Institute of Nanoenergy and Nanosystems, and Regents' Professor and Hightower Chair at Georgia Institute of Technology. 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 #5 among 100,000 scientists across all fields worldwide, #1 in Nanoscience and #2 in Materials Science. His google scholar citation is over 280,000 with an h-index of over 256.
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); Distinguished Professor Award (Highest faculty honor at Georgia Tech) (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 16.6. Details can be found at: http://www.nanoscience.gatech.edu