Professor Zi, Yunlong

Assistant Professor
B. Eng., Tsinghua University, 2009
Ph.D., Purdue University, 2014
Mechanical and Automation Engineering
Room 311 , William M.W. Mong Engineering Building
Chinese University of Hong Kong, Shatin, N.T.
Hong Kong SAR, China
(852) 3943 3093
(852) 2603 6002


Dr. Yunlong Zi received his B.Eng. degree from the Department of Materials Science and Engineering at Tsinghua University in 2009. He received his Ph.D. degree from the Department of Physics and Astronomy at Purdue University in 2014. After his graduate study, he worked as a Postdoctoral Fellow in the School of Materials Science and Engineering at Georgia Institute of Technology. Dr. Zi joined the Department of Mechanical and Automation Engineering at the Chinese University of Hong Kong as an Assistant Professor in November, 2017. He served as session chairs for Materials Research Society 2017 Spring Meeting. His current research interests include mechanical energy harvesting, high-voltage applications of triboelectric nanogenerators, self-powered system, novel energy harvesting technologies.


  • Mechanical energy harvesting: fundamental studies and experimental demonstration of converting mechanical energy to be electricity, mainly through triboelectric nanogenerators;
  • High-voltage applications of triboelectric nanogenerators: develop novel applications utilizing high-voltage output of triboelectric nanogenerators;
  • Self-powered systems: develop self-powered systems including energy harvesters, energy storage units, power-management units, and functional devices;
  • Novel energy harvesting technologies: emerging mechanical/thermal energy harvesting approaches based on newly-developed mechanisms.

Teaching by Years


  • MAEG3100 Energy Systems

Honors & Awards

  • MRS Postdoctoral Award, by Materials Research Society, 2017
  • One of "five students who are transformation makers", by Purdue University, 2013

Journal Papers (in the recent five years)

  • A. Li*, Y. Zi*, H. Guo, Z.L. Wang#, F.M. Fernández#, Triboelectric Nanogenerators for Sensitive Nano-Coulomb Molecular Mass Spectrometry, Nature Nanotechnology, 12 (5), 481-487 (2017);
  • Y. Zi*, J. Wang*, S. Wang*, S. Li, Z. Wen, H. Guo, Z.L. Wang#, Effective Energy Storage from a Triboelectric Nanogenerator, Nature Communications, 7:10987, (2016);
  • Y. Zi*, S. Niu*, J. Wang, Z. Wen, W. Tang, Z.L. Wang#, Standards and Figure-of-Merits for Quantifying the Performance of Triboelectric Nanogenerators, Nature Communications, 6:8376, (2015);
  • Y. Zi*, L. Lin*, J. Wang, S. Wang, J. Chen, X. Fan, P.K. Yang, F. Yi, Z.L. Wang#, Triboelectric-Pyroelectric-Piezoelectric Hybrid Cell for High-Efficient Energy-Harvesting and Self-Powered Sensing, Advanced Materials, 27, 2340-2347 (2015);
  • Y. Zi*, H. Guo*, Z. Wen*, M.-H. Yeh, C. Hu, Z.L. Wang#, Harvesting Low-Frequency (< 5 Hz) Irregular Mechanical Energy: A Possible Killer-Application of Triboelectric Nanogenerator, ACS Nano, 10 (4), 4797-4805 (2016);
  • Y. Zi*, K. Jung*, D.N. Zakharov, C. Yang#, Understanding Self-Aligned Planar Growth of InAs Nanowires, Nano Letters, 13 (6), 2786-2791 (2013);
  • Y. Zi#, S. Suslov, C. Yang#, Understanding Self-Catalyzed Epitaxial Growth of III-V Nanowires Towards Controlled Synthesis, Nano Letters, 17 (2), 1167-1173 (2017);
  • Y. Zi*, H. Guo*, J. Wang*, Z. Wen, S. Li, C. Hu, Z.L. Wang#, An Inductor-Free Auto-Power-Management Design Built-in Triboelectric Nanogenerators, Nano Energy, 31, 302-310 (2017);
  • Y. Zi*, C. Wu*, W. Ding, Z.L. Wang#, Maximized Effective Energy Output of Contact-Separation-Triggered Triboelectric Nanogenerators as Limited by Air Breakdown, Advanced Functional Materials, 27 (24) (2017);
  • *: co-first authors; #: corresponding author.


  • Triboelectric Nanogenerators, by Z.L. Wang, L. Lin, J. Chen, S. Niu, Y. Zi, Springer, 2016, ISBN 3319400398, 9783319400396.