简介: |
Nanogenerators, nanopiezotronics and biomimicking nanotechnology
Zhong Lin Wang
School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245, USA
* Corresponding author: E-mails: zhong.wang@mse.gatech.edu
Exploring renewable, sustainable and green energy resources is the most critical challenge to sustainable development of human civilization. At the large-scale, besides the well known energy resources that power the world today, such as petroleum, coal, hydraulic, natural gas and nuclear, active research and development are being taken in exploring alternative energy resources such as solar, geothermal, biomass, nuclear, wind, and hydrogen. At a much smaller scale, energy and technologies are desperately needed for independent and continuous operations of implantable biosensors, ultrasensitive chemical and biomolecular sensors, nanorobotics, micro-electromechanical systems, remote and mobile environmental sensors, homeland security and even portable personal electronics. This talk will focus on nanotechnologies that have been developed for harvesting energy from our living environment with a focus on mechanical energy. An introduction will be given about nanogenerators for generating electricity using sonic waves and body movements. A new field on nano-piezotronics will be introduced, which uses piezoelectric-semiconducting coupled property for fabricating novel and unique electronic devices and components.
We have also demonstrated biomimicked nanotechnology. Using 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 show macroscopic adhesive forces of ~100 N/cm2, almost ten times of that of a gecko foot, and a much stronger shear adhesion force than the normal adhesion force to ensure strong binding along the shear direction and easy lifting in the normal direction. This anisotropic force distribution is due to the shear-induced alignments of the curly segments of the nanotubes. The mimetic adhesives can be alternatively binding-on and lifting-off over various substrates for simulating the walking of a living gecko.
[1] Z.L. Wang “Self-powering nanotech”, Scientific American, January issue (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] Z.L. Wang “Nano-piezotronics”, Adv. Mater., 19 (2007) 889.
[6] Jun Zhou, Yudong Gu, Peng Fei, Wenjie Mai, Yifan Gao, Rusen Yang, Gang Bao, Zhong Lin Wang* “Flexible piezotronic strain sensor“, Nano Letters, 8 (2008) 3035-3040.
[7] Jun Zhou, Peng Fei, Yifan Gao, Yudong Gu, Jin Liu, Gang Bao, Zhong Lin Wang* “Mechanical-electrical triggers and sensors using piezolelectric microwires/nanowires”, Nano Letters, 8 (2008) 2725-2730.
[8] Liangti Qu, Liming Dai, Morley Stone, Zhenhai Xia, Zhong Lin Wang “Carbon nanotube arrays with super-strong shear binding-on and easy normal lifting-off”, Science, 322 (2008) 238-242.
[9] Jingyun Huang, Xudong Wang, Zhong Lin Wang* “Controlled replication of butterfly wings for achieving tunable photonic properties”, Nano Letters, 6 (2006) 2325 - 2331.
[10] for details: www.nanoscience.gatech.edu/zlwang
Biosketch
Dr. Zhong Lin (ZL) Wang is a Regents' Professor, COE Distinguished Professor and Director, Center for Nanostructure Characterization, at Georgia Tech. He has authored and co-authored four scientific reference and textbooks and over 540 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 25,000 times. The H-index of his citations is 75.
Dr. Wang discovered the nanobelt in 2001, which is considered to be a ground-breaking work. The paper on nanobelt was the second most cited paper in chemistry in 2001-2003 world-wide. His paper on piezoelectric nanosprings was one of the most cited papers in materials science in 2004 world-wide. His recent invention of world’s first nanogenerator will have profound impacts to implantable biosensors and molecular machines/robotics. In 1999, he and his colleagues discovered the world’s smallest balance, nanobalance, which was selected as the breakthrough in nanotechnology by the America Physical Society. He was elected to a fellow of American Physical Society in 2005, fellow of AAAS in 2006, 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, Sigma Xi 1998 and 2002 best paper awards, and the 1999 Burton Medal from Microscopy Society of America. Details can be found at: http://www.nanoscience.gatech.edu/zlwang
|
