Tag Archives: Vaporsens

Sensing fuel leaks and fuel-based explosives with a nanofibril composite

A March 28, 2016 news item on Nanowerk highlights some research from the University of Utah (US),

Alkane fuel is a key ingredient in combustible material such as gasoline, airplane fuel, oil — even a homemade bomb. Yet it’s difficult to detect and there are no portable scanners available that can sniff out the odorless and colorless vapor.

But University of Utah engineers have developed a new type of fiber material for a handheld scanner that can detect small traces of alkane fuel vapor, a valuable advancement that could be an early-warning signal for leaks in an oil pipeline, an airliner, or for locating a terrorist’s explosive.

A March 25, 2016 University of Utah news release, which originated the news item, provides a little more detail,

Currently, there are no small, portable chemical sensors to detect alkane fuel vapor because it is not chemically reactive. The conventional way to detect it is with a large oven-sized instrument in a lab.

“It’s not mobile and very heavy,” Zang [Ling Zang, University of Utah materials science and engineering professor] says of the larger instrument. “There’s no way it can be used in the field. Imagine trying to detect the leak from a gas valve or on the pipelines. You ought to have something portable.”

So Zang’s team developed a type of fiber composite that involves two nanofibers transferring electrons from one to the other.

That kind of interaction would then signal the detector that the alkane vapor is present. Vaporsens, a University of Utah spinoff company, has designed a prototype of the handheld detector with an array of 16 sensor materials that will be able to identify a broad range of chemicals including explosives.  This new composite material will be incorporated into the sensor array to include the detection of alkanes. Vaporsens plans to introduce the device on the market in about a year and a half, says Zang, who is the company’s chief science officer.

Such a small sensor device that can detect alkane vapor will benefit three main categories:

  • Oil pipelines. If leaks from pipelines are not detected early enough, the resulting leaked oil could contaminate the local environment and water sources. Typically, only large leaks in pipelines can be detected if there is a drop in pressure. Zang’s portable sensor — when placed along the pipeline — could detect much smaller leaks before they become bigger.
  • Airplane fuel tanks. Fuel for aircraft is stored in removable “bladders” made of flexible fabric. The only way a leak can be detected is by seeing the dyed fuel seeping from the plane and then removing the bladder to inspect it. Zang’s sensors could be placed around the bladder to warn a pilot if a leak is occurring in real time and where it is located.
  • Security. The scanner will be designed to locate the presence of explosives such as bombs at airports or in other buildings. Many explosives, such as the bomb used in the Oklahoma City bombing in 1995, use fuel oils like diesel as one of its major components. These fuel oils are forms of alkane.

The research was funded by the Department of Homeland Security, National Science Foundation and NASA. The lead author of the paper is University of Utah materials science and engineering doctoral student Chen Wang, and [Benjamin] Bunes is the co-author.

Here’s a link to and a citation for the paper,

Interfacial Donor–Acceptor Nanofibril Composites for Selective Alkane Vapor Detection by Chen Wang, Benjamin R. Bunes, Miao Xu, Na Wu, Xiaomei Yang, Dustin E. Gross, and Ling Zang. ACS Sens DOI: 10.1021/acssensors.6b00018 Publication Date (Web): March 09, 2016

Copyright © 2016 American Chemical Society

This paper is behind a paywall.

Bomb-sniffing and other sniffing possibilities from Utah (US state)

A Nov. 4, 2014 news item on Phys.org features some research in Utah on the use of carbon nanotubes for sensing devices,

University of Utah engineers have developed a new type of carbon nanotube material for handheld sensors that will be quicker and better at sniffing out explosives, deadly gases and illegal drugs.

A carbon nanotube is a cylindrical material that is a hexagonal or six-sided array of carbon atoms rolled up into a tube. Carbon nanotubes are known for their strength and high electrical conductivity and are used in products from baseball bats and other sports equipment to lithium-ion batteries and touchscreen computer displays.

Vaporsens, a university spin-off company, plans to build a prototype handheld sensor by year’s end and produce the first commercial scanners early next year, says co-founder Ling Zang, a professor of materials science and engineering and senior author of a study of the technology published online Nov. 4 [2014] in the journal Advanced Materials.

The new kind of nanotubes also could lead to flexible solar panels that can be rolled up and stored or even “painted” on clothing such as a jacket, he adds.

Here’s Ling Zang holding a prototype of the device,

Ling Zang, a University of Utah professor of materials science and engineering, holds a prototype detector that uses a new type of carbon nanotube material for use in handheld scanners to detect explosives, toxic chemicals and illegal drugs. Zang and colleagues developed the new material, which will make such scanners quicker and more sensitive than today’s standard detection devices. Ling’s spinoff company, Vaporsens, plans to produce commercial versions of the new kind of scanner early next year. Courtesy: University of Utah

Ling Zang, a University of Utah professor of materials science and engineering, holds a prototype detector that uses a new type of carbon nanotube material for use in handheld scanners to detect explosives, toxic chemicals and illegal drugs. Zang and colleagues developed the new material, which will make such scanners quicker and more sensitive than today’s standard detection devices. Ling’s spinoff company, Vaporsens, plans to produce commercial versions of the new kind of scanner early next year. Courtesy: University of Utah

A Nov. 4, 2014 University of Utah news release (also on EurekAlert), which originated the news item, provides more detail about the research,

Zang and his team found a way to break up bundles of the carbon nanotubes with a polymer and then deposit a microscopic amount on electrodes in a prototype handheld scanner that can detect toxic gases such as sarin or chlorine, or explosives such as TNT.

When the sensor detects molecules from an explosive, deadly gas or drugs such as methamphetamine, they alter the electrical current through the nanotube materials, signaling the presence of any of those substances, Zang says.

“You can apply voltage between the electrodes and monitor the current through the nanotube,” says Zang, a professor with USTAR, the Utah Science Technology and Research economic development initiative. “If you have explosives or toxic chemicals caught by the nanotube, you will see an increase or decrease in the current.”

By modifying the surface of the nanotubes with a polymer, the material can be tuned to detect any of more than a dozen explosives, including homemade bombs, and about two-dozen different toxic gases, says Zang. The technology also can be applied to existing detectors or airport scanners used to sense explosives or chemical threats.

Zang says scanners with the new technology “could be used by the military, police, first responders and private industry focused on public safety.”

Unlike the today’s detectors, which analyze the spectra of ionized molecules of explosives and chemicals, the Utah carbon-nanotube technology has four advantages:

• It is more sensitive because all the carbon atoms in the nanotube are exposed to air, “so every part is susceptible to whatever it is detecting,” says study co-author Ben Bunes, a doctoral student in materials science and engineering.

• It is more accurate and generates fewer false positives, according to lab tests.

• It has a faster response time. While current detectors might find an explosive or gas in minutes, this type of device could do it in seconds, the tests showed.

• It is cost-effective because the total amount of the material used is microscopic.

This study was funded by the Department of Homeland Security, Department of Defense, National Science Foundation and NASA. …

Here’s a link to and a citation for the research paper,

Photodoping and Enhanced Visible Light Absorption in Single-Walled Carbon Nanotubes Functionalized with a Wide Band Gap Oligomer by Benjamin R. Bunes, Miao Xu, Yaqiong Zhang, Dustin E. Gross, Avishek Saha, Daniel L. Jacobs, Xiaomei Yang, Jeffrey S. Moore, and Ling Zang. Advanced Materials DOI: 10.1002/adma.201404112 Article first published online: 4 NOV 2014

© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

For anyone curious about Vaporsens, you can find more here.