Nanotube-producing bacteria show manufacturing promise

December 7, 2007
Nanotube-producing bacteria show manufacturing promise
Genus Shewanella. The nanotube filaments produced by biological means could point toward semiconductor manufacturing processes with a smaller energy and environmental footprint. Image credit: Hor-Gil Hur, GIST

Two engineers at the University of California, Riverside are part of a binational team that has found semiconducting nanotubes produced by living bacteria – a discovery that could help in the creation of a new generation of nanoelectronic devices.

The research team believes this is the first time nanotubes have been shown to be produced by biological rather than chemical means. It opens the door to the possibility of cheaper and more environmentally friendly manufacture of electronic materials.

Study results appear in today's issue of the early edition of the Proceedings of the National Academy of Sciences.

The team, including Nosang V. Myung, associate professor of chemical and environmental engineering in the Bourns College of Engineering, and his postdoctoral researcher Bongyoung Yoo, found the bacterium Shewanella facilitates the formation of arsenic-sulfide nanotubes that have unique physical and chemical properties not produced by chemical agents.

“We have shown that a jar with a bug in it can create potentially useful nanostructures,” Myung said. “Nanotubes are of particular interest in materials science because the useful properties of a substance can be finely tuned according to the diameter and the thickness of the tubes.”

The whole realm of electronic devices which power our world, from computers to solar cells, today depend on chemical manufacturing processes which use tremendous energy, and leave behind toxic metals and chemicals. Myung said a growing movement in science and engineering is looking for ways to produce semiconductors in more ecologically friendly ways.

Two members of the research team, Hor Gil Hur and Ji-Hoon Lee from Gwangju Institute of Science and Technology (GIST), Korea, first discovered something unexpected happening when they attempted to remediate arsenic contamination using the metal-reducing bacterium Shewanella. Myung, who specializes in electro-chemical material synthesis and device fabrication, was able to characterize the resulting nano-material.

The photoactive arsenic-sulfide nanotubes produced by the bacteria behave as metals with electrical and photoconductive properties. The researchers report that these properties may also provide novel functionality for the next generation of semiconductors in nano- and opto-electronic devices.

In a process that is not yet fully understood, the Shewanella bacterium secretes polysacarides that seem to produce the template for the arsenic sulfide nanotubes, Myung explained. The practical significance of this technique would be much greater if a bacterial species were identified that could produce nanotubes of cadmium sulfide or other superior semiconductor materials, he added.

“This is just a first step that points the way to future investigation,” he said. “Each species of Shewanella might have individual implications for manufacturing properties.”

Source: University of California - Riverside

Explore further: New 'electronic nose' nano-sensor being developed for food safety, health

Related Stories

Engineers develop 'electronic nose' prototype

August 21, 2012

( -- Research by Nosang Myung, a professor at the University of California, Riverside, Bourns College of Engineering, has enabled a Riverside company to develop an "electronic nose" prototype that can detect small ...

Using cell phones to detect harmful airborne substances

April 4, 2012

The lab of a University of California, Riverside Bourns College of Engineering professor was named on Tuesday, April 3 after Innovation Economy Corporation, a Riverside company that plans to commercialize his research focused ...

Rice Refining Production of Pure Nanotube Fibers

September 5, 2004

Rice University scientists are refining pioneering chemical production methods used to make pure carbon nanotube fibers. Research appearing in tomorrow's issue of the journal Science describes the scalable production techniques, ...

Recommended for you

Touchless displays superseding touchscreens?

October 2, 2015

While touchscreens are practical, touchless displays would be even more so. That's because, despite touchscreens having enabled the smartphone's advance into our lives and being essential for us to be able to use cash dispensers ...

Physicists map the strain in wonder material graphene

September 29, 2015

This week, an international group of scientists is reporting a breakthrough in the effort to characterize the properties of graphene noninvasively while acquiring information about its response to structural strain.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.