清华大学材料科学与工程研究院《材料科学论坛》

学术报告

报告题目及报告人：

   Prof. Zhong Lin (Z.L.) Wang

(School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta USA)

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联系人：唐子龙 62772623

报告2

Abstract:

Developing novel technologies for wireless nanodevices and nanosystems are of critical importance for sensing, medical science, defense technology and even personal electronics. It is highly desired for wireless devices and even required for implanted biomedical devices to be self-powered without using battery. Therefore, it is essential to explore innovative nanotechnologies for converting mechanical energy (such as body movement, muscle stretching), vibration energy (such as acoustic/ultrasonic wave), and hydraulic energy (such as body fluid and blood flow) into electric energy that will be used to power nanodevices without using battery. We have demonstrated an innovative approach for converting nano-scale mechanical energy into electric energy by piezoelectric zinc oxide nanowire (NW) arrays. The operation mechanism of the electric generator relies on the unique coupling of piezoelectric and semiconducting dual properties of ZnO as well as the elegant rectifying function of the Schottky barrier formed between the metal tip and the NW. Based on this mechanism, we have recently developed DC nanogenerator driven by ultrasonic wave in bio-fluid. We have also used textile fibers for energy harvesting and have invented muscle driven nanogenerators.

The driving force for holding gecko lizards on a vertical solid surface to defy gravity comes from its remarkable feet and toes that are made of aligned microscopic elastic hairs. Using a rationally designed carbon nanotube arrays that are dominated by a straight body-segment but with curly entangled top, we have created gecko-foot-mimetic dry adhesives that showed the highest reported macroscopic adhesive force of ~100 N/cm², almost ten times of that of a gecko foot (10 N/cm²). More importantly, these hierarchically-structured nanotube adhesives exhibited a much stronger shear adhesion force than the normal adhesion force (~10 N/cm²) to ensure a strong binding along the shear direction and easy lifting in the normal direction. The mimetic adhesives can be alternatively binding-on and lifting-off for simulating the walking of a living gecko.

[1] Z.L. Wang “Self-powering nanotech”, Scientific American, 298 (2008) 82-87.

[2] Z.L. Wang and J.H. Song  ^“Piezoelectric Nanogenerators Based on Zinc Oxide Nanowire Arrays”, Science, 312 (2006) 242-246.

[3] X.D. Wang, J.H. Song J. Liu, and Z.L. Wang “Direct current nanogenerator driven by ultrasonic wave”, Science, 316 (2007) 102-105.

[4] Yong Qin, Xudong Wang and Zhong Lin Wang ”Microfiber-Nanowire Hybrid Structure for Energy Scavenging”, Nature, 451 (2008) 809-813.

[5] R.S. Yang, Y. Qin, L.M. Dai and Zhong Lin Wang * “Flexible charge-pump for power generation using laterally packaged piezoelectric-wires”, Nature Nanotechnology, 4 (2009) 34-39.

[6] L.T. Qu, L.M. Dai, M. Stone, Z.H. Xia, Z.L. Wang “Carbon nanotube arrays with super-strong shear binding-on and easy normal lifting-off”, Science, 322 (2008) 238-242.

[7] Top 10 future technologies by New Scientists: http://www.newscientist.com/article/mg20126921.800-ten-scifi-devices-that-could-soon-be-in-your-hands.html?full=true

[8] Research supported by DARPA, BES DOE, NSF, NASA and Emory-Georgia Tech CCNE from NIH.

CV:

Dr. Wang is a Regents' Professor and COE Distinguished Professor at Georgia Tech. He has authored and co-authored four scientific references and textbooks, published over 560 peer reviewed journal articles, 55 review papers and book chapters, edited and co-edited 14 volumes of books on nanotechnology, and held 20 patents and provisional patents. Dr. Wang is the world’s top 25 most cited authors in nanotechnology from 1992-2002 (ISI, Science Watch). His entire publications have been cited for over 26,000 times. The H-index of his publications is 77. He is a fellow of American Physical Society and fellow of AAAS, and he has received the 2001 S.T. Li prize for Outstanding Contribution in Nanoscience and Nanotechnology, the 2000 and 2005 Georgia Tech Outstanding Faculty Research Author Awards, Sigma Xi 2005 sustain research awards, and the 1999 Burton Medal from Microscopy Society of America. for details visit: http://www.nanoscience.gatech.edu/zlwang/