Tech research labeled pioneer of important technologies

Robert Nesmith
Communications & Marketing

	ABOVE: Materials Science and Engineering Regents’ Professor Zhong Lin Wang displays flexible charge pumps that are able to produce alternating current through the stretching and relaxing of zinc oxide wires. BELOW: Schematic shows the change in vertically-aligned multi-walled carbon nanotubes during adhesion measurements.

The January issue of New Scientist played the prognosticator, naming the 10 technologies that, in 30 years, will be as important and ubiquitous as the cell phone—which in turn was created 30 years ago. Research in the development of two items on the magazine’s list was pioneered at Georgia Tech.

Nos. 4 and 5 on the list—“Spider vs Gecko” and “You Power,” respectively—have at their roots research conducted at Georgia Tech. On both, Materials Science and Engineering Regents’ Professor Zhong Lin Wang played a significant role.

“Spider vs Gecko” chronicles the search for an adhesive consisting of nanoscale “hairs” that could support a large amount of weight. In searching for the best structure and framework for such a design, researchers from the University of Dayton, Tech, the Air Force Research Laboratory and the University of Akron designed an improved material that is 10 times stronger than a real gecko’s foot at resisting perpendicular shear forces.

“The model for that was used in the growing of carbon nanotubes, which grow like grass,” Wang said. “When short, it grows everywhere. When tall … they achieve very good alignment.” The key to the design, Wang says, is the fiber’s contact with the substrate. In 2008 his research led to the use of multi-walled carbon nanotubes with “curly, entangled tops,” which mimics the looped, padded feet of a gecko’s foot.

The future impact of this technology, Wang says, is not for a window walker or a spandex-clothed crime fighter, but for adhesion on the nanoscale, where welding and soldering would be ineffective, and for use in the vacuum of space, where a dry adhesive would be necessary. Wang worked with Dayton Professor Liming Dia on the research, sponsored by the National Science Foundation and the U.S. Air Force Research Laboratory at Wright-Patterson Air Force Base near Dayton, Ohio.

His major research at Tech has focused on “You Power”—No. 5 on the magazine’s top 10 list—in which wearable fabric is constructed of zinc-oxide nanowires grown on Kevlar strands. When the material bends or compresses, a miniscule current is generated through the wires. While only producing a very small amount of current now, Wang noted that technology is reaching major limitations, in that while everything is getting smaller, the technology standards and memory capacity are increasing. “When everything else is so small, the battery or power source needs to be small as well,” he said. “However, usually as something decreases in size, its power consumption decreases as well.”

“Our body is the best energy source,” Wang said. “[The question is] how do we convert this to external energy. [Tech is] the pioneer in this field. We are exploring how to convert body movement into electric energy.” Wang says some of the applications for this wearable technology include providing power for cell phones.

Wang, the director of the Center for Nanostructure Characterization (CNC), has been on the faculty at Tech since 1995. Other research has cited his body of publications more than 26,000 times.

For more information

Materials Science and Engineering