Aug. 6, 2002 — Patent filings on carbon nanotubes are keeping pace proportionately with the growing number of academic papers published on nanotubes, according to a review in this week’s journal Science.
That suggests industry’s interest in the versatile molecule is increasing steadily. While patenting doesn’t ensure commercialization, it certainly improves its chances, the lead
Nanotube patents have been filed in these applications.
“The past is often a good way to predict the future,” said Ray Baughman, director of the NanoTech Institute at the University of Texas at Dallas and a carbon nanotube researcher. “There is a commonality in the way technology evolves.”
Baughman wrote the review with colleagues Anvar Zakhidov, a physicist at UT-Dallas and a member of the institute, and Walt de Heer, a physicist at the Georgia Institute of Technology. The review details the latest findings on nanotube properties and limitations, plus their potential applications and existing products.
The publishing and patenting results, while only a segment of the overall review, are significant because they foreshadow economic growth. Economists see publishing and patenting as indicators of scientific activity and its transfer into industry. Some economists argue that innovation based on scientific and technological discoveries gives nations a competitive edge and fuels prosperity.
Carbon nanotubes, first identified in 1991, offer a number of attractive properties. They form as either single tubes (single-wall carbon nanotubes) or tubes within tubes (multiwall carbon nanotubes). They are much stronger than steel at a fraction of its weight, thermally and electrically conductive — or in some cases semiconductors — and are biocompatible. Recent research shows they have optical properties, too; they fluoresce in the near-infrared spectrum.
Their potential applications include strong, lightweight materials, energy storage and energy conversion devices, electronics, sensors and field emission sources for flat panel displays and cathodes. The latter two applications are based on nanotubes’ ability to release large numbers of electrons from their tips when a voltage is applied. As Baughman writes in the review, some applications are already being commercialized while others still face a variety of challenges.
The researchers found about 1,500 scientific papers were published in 2001, up from about 1,100 in 2000 and about 700 in 1999. Patent filings and issuances totaled more than 200 in 2001, about 120 in 2000 and about 50 in 1999. The steady growth kicked in after 1993, the year two research groups unveiled techniques for producing research quantities of nanotubes.
The majority of filings and issuances — 41 percent — cover the synthesis and processing of tubes, according to the team’s analysis. But two applications already being commercialized showed strong patenting activity. Inventions dealing with carbon nanotubes and electron emission (displays, etc.) garnered 25 percent of the filings, while composites chalked up another 9 percent. The remainder went to batteries and energy storage devices (7 percent), electronics (6 percent), hydrogen storage (6 percent), sensors (3 percent) and “other” (3 percent).
Japanese inventors hold the lead in the percentage of total patents filed, but 90 percent of those patents have yet to be filed in other countries, the researchers found. Inventors in the United States own 49 percent of multicountry patents.
The findings mirror other studies looking at nanotechnology and publishing/patenting trends. In a paper published recently in Nanotechnology magazine, European Commission analysts found that nanotechnology publishing and patenting is growing somewhat in parallel worldwide. They concluded nanotechnology in general was neither scientifically nor technologically close to commercialization.
Baughman, who was a corporate fellow at Honeywell International before joining UT-Dallas in 2001, holds 51 U.S. patents and has published 173 research papers. He makes what he calls artificial muscles — fibers spun from nanotubes that expand or contract when injected with a charge. He received funding from the Defense Advanced Research Projects Agency (DARPA) to develop nanotube actuators and capacitors, which are used for storing energy.
“You could weave the capacitors into electronic textiles for soldiers,” Baughman said. The material could be used in uniforms to store energy but also might double as a protective clothing, based on nanotubes’ strength and light weight.